5 Polish Conference „Graphene and 2D...

V Krajowa Konferencja „Grafen i inne materiały 2D”

5th Polish Conference „Graphene and 2D materials”

19-21 września 2019 r.

Szczecin

ORGANIZATORZY

Katedra Fizykochemii Nanomateriałów

Wydział Technologii i Inżynierii Chemicznej

Zachodniopomorski Uniwersytet Technologiczny w Szczecinie

Wydział Fizyki

Uniwersytet Warszawski

MIEJSCE KONFERENCJI

Centrum Dydaktyczno-Badawcze Nanotechnologii ZUT

al. Piastów 45, Szczecin

SZCZECIN 2019

2

Redakcja: Ewa Mijowska, Beata Zielińska, Wojciech Kukułka

ISBN 978-83-7663-294-0

Materiały wydane przez Katedrę Fizykochemii Nanomateriałów WTiICH ZUT w Szczecinie na

podstawie streszczeń nadesłanych przez autorów

Szczecin 2019

3

KOMITET ORGANIZACYJNY KONFERENCJI

Przewodnicząca

prof. dr hab. Ewa Mijowska

Sekretarze naukowi

prof. dr hab. inż. Mirosława El Fray

prof. dr hab. inż. Ryszard J. Kaleńczuk

Sekretarze organizacyjni

dr hab. inż. Beata Zielińska

dr inż. Karolina Szymańska

dr inż. Karolina Wenelska

Członkowie

dr inż. Marcin Biegun

mgr inż. Martyna Trukawka

mgr inż. Martyna Baca

mgr inż. Wojciech Kukułka

mgr inż. Klaudia Maślana

mgr inż. Krzysztof Sielicki

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KOMITET NAUKOWY KONFERENCJI

dr hab. Maria Augustyniak-Jabłokow

dr hab. inż. Leszek Bryja, prof. nadzw. PWr

dr hab. inż. Agnieszka Jastrzębska

prof. dr hab. inż. Ryszard J. Kaleńczuk

prof. dr hab. Zbigniew Klusek

prof. dr hab. Piotr Kossacki

prof. dr hab. Sebastian Maćkowski

prof. dr hab. Jacek A. Majewski

prof. dr hab. Ewa Mijowska

prof. dr hab. inż. Andrzej Olszyna

prof. dr hab. Andrzej Wysmołek

dr hab. inż. Mariusz Zdrojek, prof. nadzw. PW

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Spis treści

WYSTĄPIENIA USTNE ......................................................................................................................... 7

Properties of the Cu multi-layer graphene composites produced by high pressure torsion .............. 8

N-doped activated carbon derived from carbonized furfuryl alcohol in CO2 and ethylene sorption 10

New eco-friendly batteries based on carbon nanotubes .................................................................. 12

Plasmon enhanced photocurrent generation of Photosystem I coupled with graphene electrode 13

Impact of adsorbed gases on the coherence time of paramagnetic centers in reduced graphene

oxide .................................................................................................................................................. 14

Semipermeable membranes based on graphene ............................................................................. 16

Application of noncovalent dye/graphene based material in photocatalysis .................................. 17

In vitro biocompatibility of g-C3N4, graphene oxide and reduced graphene oxide nanosheets –

effect of lateral sizes and nanomaterials concentration ................................................................... 19

On-surface synthesis and characterization of nanographenes ......................................................... 20

Supramolecular complexes of graphene oxide with porphyrins ...................................................... 21

Influence of graphene defects on properties of grafted single molecule magnets – ab initio studies

........................................................................................................................................................... 23

Probing interactions between AlxGa1-xN/GaN axial heterostructure nanowires and graphene by

electroreflectance and contactless transport ................................................................................... 24

Transport properties of graphene oxide thin films during reduction process .................................. 26

Tuning the cytotoxicity of Ti3C2 (MXene) flakes by post-delamination surface modifications ......... 28

Extraordinary Zoo of 2D materials and accessing their unique properties in state-of the-art

dispersions via Liquid Phase Exfoliation ............................................................................................ 29

Upconverted electroluminescence in van der Waals heterostructures ........................................... 30

Lateral superlattices of graphene and boron nitride ........................................................................ 32

Theoretical studies of the optical properties of MnPS3 – a 2D magnetic material ........................... 33

Theoretical studies of mixed phosphorus trichalcogenides .............................................................. 34

Theoretical studies of van der Waals heterostructure NiPS3/graphene ........................................... 35

Functionalized exfoliated boron nitride nano-flakes – in vivo and in vitro study ............................. 36

Polarization resolved Raman spectroscopy of 1T-TaS2 ..................................................................... 37

How to snapshot a phase transition? Thermoelectric properties of 1T-TaS2 ................................... 38

Photodetectors based on transition metal dichalcogenides ............................................................ 40

Design and application of g-C3N4 based structures towards photocatalytic processes .................... 41

Optical properties of nanocomposites based on various 2D materials in terahertz regime ............ 42

Exfoliation of ultrathin epitaxial layers of boron nitride grown by MOVPE ...................................... 43

6

Optical and structural characterization of boron nitride grown by MOVPE ..................................... 44

“Real-World” Waste Polymers from Bottles for 2D Porous Carbons in Supercapacitors ................. 45

SESJA POSTEROWA ............................................................................................................................ 46

Application of bacterial cellulose produced by Komagataeibacter xylinus as a cell growth substrate

for bovine mammary epithelial cells (MAC-T) ................................................................................... 47

A preliminary in vitro study on boron nitride nanocomposites loaded with 10-hydroxycamptothecin

on mammalian cells ........................................................................................................................... 49

The influence of carbon nanotubes on rheological properties of model pulmonary surfactant ..... 51

Averting 2D Ti3C2 and Ti2C MXenes’ cytotoxicity by controlled adsorption of collagen ................... 53

Adhesion of vanadium phthalocyanine to graphene and gold surfaces – first-principles study ...... 54

Theoretical and spectroscopic characterization of porphyrin/graphene oxide nanohybrid ............ 55

Thermal properties of layered materials probed by Raman spectroscopy ....................................... 57

New hybrid materials based on carbon nanotubes and metal alloys ............................................... 58

Studies of graphene/1T-TaS2 and 1T-TaS2/graphene heterostructures by

STM/STS/LEED/ARPES/DFT technics ................................................................................................. 59

Photoconductivity of boron nitride layers grown by MOVPE ........................................................... 60

Extraordinary transport properties of disordered graphene structures of annealed charcoal ........ 62

SWCNTs and MWCNTs as co-catalysts of g-C3N4 for photocatalytic H2 evolution - comparative study

........................................................................................................................................................... 64

Flammability and thermal conductivity of tungsten disulfide/carbon nanotube nanocomposites . 65

MOF-5 derived carbon as material for CO2 adsorption..................................................................... 66

CaCO3 template assistant to synthesize 2D porous carbon flakes from intumescent flame

retardants for high-performance supercapacitors............................................................................ 67

Controlled synthesis of Ni-Al layered double hydroxide on exfoliated molybdenum disulfide

nanosheets and its application for flame retarded polystyrene composites ................................... 68

Highly Efficient Conversion of Plastic Waste into Carbon Nanosheets and Enlarged its Interlayer

Spacing for High Electrochemical Performance ................................................................................ 69

WS2 and MoS2 rods as high efficient electrocatalyst in oxygen evolution reaction ......................... 70

Electrochemical Nitrogen Reduction Reaction conducted on MoS2-Fe_rods heterocatalyst .......... 71

The modification of carbon materials for methane storage ............................................................. 72

Tailoring the textural properties of an activated carbon .................................................................. 74

Activated carbon prepared from mistletoe leaves ........................................................................... 76

INDEKS AUTORÓW ............................................................................................................................ 78

7

WYSTĄPIENIA USTNE

Wystąpienia ustne V KK Grafen2D, Szczecin, 19-21.09.2019

8

Properties of the Cu multi-layer graphene composites produced by high

pressure torsion

T. Czeppe1, L. Litynska-Dobrzynska1, G. Korznikova2, P. Ozga1, R. Socha3

1Institute of Metallurgy and Materials Sciences, Polish Academy of Sciences,

Reymonta 25 St. 30-059 Krakow, Poland 2Institute for the Metals Superplasticity Problems, Russian Academy of Sciences, Halturina St., Ufa, Russia

3 Intitute of the Catalysis and Physical Properties of the Surfaces, Polish Academy of Sciences,

Niezapominajek St., Krakow, Poland

e-mail : [email protected]

The method of preparation of the Cu- graphene composites through the intensive

deformation, with no noticeable temperature increase was applied. The high pressure torsion

technique (HPT) was used. Two types of the procedures were applied. The first one

concerned powder-type samples, not introducing mechanical synthesis as a preliminary

process and the second consolidation of the subsequent layers of copper foils with graphene.

Both Cu-graphene powder composites from the mixed powders and layered composites from

thin Cu foils separated by the graphene powder were successfully consolidated with

application of the slightly different parameters.

In all cases the achieved samples were small, having dimensions in the range of 10 mm

(powder samples) or 20 mm (layer samples) in diameter and very thin as well but revealed

homogenous microstructure. The critical value of the deformation for synthesis was

calculated and microstructure investigated by XRD and TEM. The investigations with the X-

ray photoelectron spectroscopy (XPS) revealing types of the atomic bounds formed and

Raman spectroscopy supplying information of the carbon-based products and defects density

in the composites were also performed. The general conclusions were that the intensive

deformation introduced by HPT may be successfully applied for the synthesis of the

homogenous composite structures but it is necessarily to apply parameters properly chosen,

both the hydrostatic pressure and rotation numbers. The method of HPT do not form any

additional compounds or impurities itself, but includes all the impurities from the powders

surfaces, e.g. organic solvents and oxides to the volume of the sample. Due to the intensive

shearing the amount of the monolayer graphene in nano-graphite looks to increase but

together with the large dispersion of the GN particles and high density of the defects

introduced. In the case of the powder Cu-graphene composites, the elastic properties

increased greatly in comparison with the Cu samples consolidated in the same way while in

the case of the layer composite the very high increase in micro-hardness was achieved

together with loss of ductility.

Fig.1. TEM (a) and HREM (b) microstructures, visible graphene particles of about 10 nm size.

• a • b

V KK Grafen2D, Szczecin, 19-21.09.2019 Wystąpienia ustne

9

Fig.2. Raman spectra of graphene from the Cu-GN powder composite in the range of the D, G and D’ bands.

References:

1] K.S. Novoselov, A.K. Geim, S.V. Morozov, D. Jiang, Y. Zhang, S.V. Dubonos at. al., Science 306(5696), 666

(2004).

[2] A.K. Geim, Science 324 (5934) 1530 (2009).

[3] A.K. Geim, K.S. Novoselov, Nat Mater 6(3) 183 (2007).

[4] K.S. Novoselov, Z. Jiang, Y. Zhang, S.V. Morozov, H.L. Stormer, U.Zeitler, et al., Science 315(5817) 1379

(2007).

[5] C.G. Rocha at.al. in: Graphene, Synthesis and Applications Eds. W. Choi, J. Lee, CRC Press, Boca Raton,

London, New York 2012, p.1.

[6] C.G. Lee, X.D. Wei, J.W. Kysar, J. Hone, Science 321(5887) 385 (2008).Electric

[7] D. Lahiri, A. Agarwal, in: Graphene, Synthesis and Applications Eds. W. Choi, J. Lee, CRC Press, Boca

Raton, London, New York 2012, p.188.

[8] C.G. Rocha at.al. in: Graphene, Synthesis and Applications Eds. W. Choi, J. Lee, CRC Press, Boca Raton,

London, New York 2012, p.10.

[9] S. Pei, H-M. Cheng, Carbon (2011) doi:10.1016/j.carbon.2011.11.010

[10] T. Otsuji, T. Suemitsu, A. Satou, M. Suemitsu, E. Sano, M. Ryzhii, V. Ryzhii in: Graphene, Synthesis and

Applications Eds. W. Choi, J. Lee, CRC Press, Boca Raton, London, New York 2012, p.85.

[11] R.Z. Valiev, A.P. Zhilyaev, T.B. Langdon, in: Bulk Nanostructured Materials TMS Wiley, Hoboken, New

Jersey 2014 p.88.

[12] J. Sort, D.C. Ile, A.P. Zhilyaev, A. Concustell, T. Czeppe, M. Stoica, S. Suriñach, J. Eckert, M.D. Baró,

Sripta Mat. 50 1221 (2004).

[13] T. Czeppe, G.F. Korznikova, A.W. Korznikov, L. Litynska-Dobrzynska, Z. Światek, Archives of

Metallurgy and Materials 58 447 (2013).

[14] R.Z. Valiev, A.P. Zhilyaev, T.B. Langdon, in: Bulk Nanostructured Materials TMS Wiley, Hoboken, New

Jersey 2014 p.30.

[15] M.L. Chen, Ch-Y. Park, J-G. Choi, W-Ch. Oh, J. Korean Ceramic Soc. 48, 147, (2011).

[16] G. Wang, J. Yang, J. Park, X. Gou, B. Wang, H. Liu, J. Yao, J. Phys. Chem, C 112, 8192, (2008).

[17] Y. Zhou, Z.Q. Li, J All. Comp. 414, 107, (2006).

[18] A.C. Ferrari, J.C. Meyer, V. Scardaci at.al., PRL 97 187401 (2006).

[19] I. Childres, L.A. Jauregui, W. Park, H. Cao, Y.P. Chen: Raman Spectroscopy of Graphene and Related

Materials, Chapter 19 in: New Developments in Photon and Materials Research, Eds. Joon I. Jang, Nova

Science Pub Inc, 2013.

Acknowledgements: The work was financed by the Project GRAF-TECH/NCBR/10/29/ 2013 and partially

realized in frame of the bilateral cooperation project between IMMS PAS and IMSP RAS 2014-2019. The

support of the SINTERCER project is gratefully acknowledged. The experimental work was done in the

laboratories of IMMS PAS affiliated by the Polish Accreditation Centre and IMSP RAS.


10

N-doped activated carbon derived from carbonized furfuryl alcohol in CO2

and ethylene sorption

R.J. Wróbel, M. Zgrzebnicki

West Pomeranian University of Technology, Szczecin,

Faculty of Chemical Technology and Engineering, Piastów Ave. 42, 71-065 Szczecin, Poland

e-mail: [email protected]

Carbonaceous materials are widely used in many fields. For instance, materials, which

were only carbonized, but not activated can be used as anodes in batteries and in

supercapacitors. Such a carbonized materials exhibit relatively low specific surface area

(SBET) and low porosity. On the other hand, activation (physical, chemical or combined) can

provide material with high SBET and well developed porous structure, making the material

suitable for sorption applications, including gas separation and gas storage. Depending on

activation parameters different properties, like pore size distribution or surface chemistry,

might be obtained. Nevertheless, the origin of carbon precursor is also a crucial factor in a

production of carbonaceous anodes or carbonaceous sorbents.

Theoretically, almost all organic materials containing carbon can be used as a precursor,

for instance cherry and olive stones, wood, coal, residual sugar and biomass. However, those

materials may contain some inorganic matter, also known as ash. Thus, additional treatment

like acid washing is sometimes required to remove it. In many applications, where purity of

carbon should be defined on ppm level, the purification of natural origin material can be very

expensive or even not feasible. The high purity carbonaceous materials can be obtained from

polymeric precursor, which in general is characterized with lower content of inorganic

impurities than material of natural origin. Such a precursor provides better recurrence of the

sample production (properties, yield), due to same composition of starting polymers.

Moreover, each modification of production procedure should lead to the same results, because

in contrast to natural origin precursors well defined polymers are readily available.

Additionally, it is possible to obtain doped material by addition of some specific compounds

at polymerization stage. This ensures that carbonized and later activated material is

homogeneous in respect to doping element.

In this study the development of porous structure was investigated in order to obtaining a

suitable material for adsorption of particular gas. Two different types of gases were used to

determine sorption properties – CO2 and C2H4. The uptakes as a function of temperature are

presented in Fig. 1.

The importance of ethene sorption is related with its impact on ripening of fruits and

vegetables. Its accumulation leads to fasten maturation. On the other hand the CO2 is

connected with global warming. Thus, one can find presented results as useful for preparing

materials with purpose of gas storage. In case of carbon dioxide, its sequestration has been

developed for several years. It is known as Carbon Capture and Storage (CCS). Its purpose is

to reduce emission of greenhouse gases and their permanent storage.

The precise aim of this study was to present the influence of nitrogen doping and changes in

porous structure taking place during physical activation on sorption performance of activated

carbon obtained from polymer precursor and activated in CO2 atmosphere. Material was

tested on the ethene and carbon dioxide sorption, due to their wide application in industry and

the need of sequestration of them through sorption.


11

Figure 1. Adsorption isobars from TGA: (A) carbon dioxide sorption, (B) ethene sorption.

The summary of the study is: Gas uptakes were measured for C2H4 at 303 K and for CO2

at 273 K and 303 K. The determined uptakes for best samples are 2.9, 3.5 and 1.8 mmol/g

respectively. Highest sorption of C2H4 and CO2 were obtained for samples with different pore

size distributions. This indicates that the crucial pore size responsible for sorption of these

gases is different.

The first main conclusion of presented results is that nitrogen doping enhances CO2 sorption

capacity. The differences in sorption of samples FA-N-20 and FA-N-73 proves that

conclusion. Both samples contain the same cumulative volume 0.17 cm3/g of pores of

diameter up to 0.8 nm i.e. crucial for CO2 sorption at 273 K under 1 bar. However the samples

differs in respect of surface nitrogen content as proven by XPS. The samples contain 2 and 1

at.% of surface nitrogen respectively. As a result, CO2 sorption of material FA-N-73 is lower

compared to FA-N-20. The nitrogen was present as pyridinic, pyrrolic, graphitic and N-oxide

as confirmed by XPS.

The second main conclusion is that physical activation of carbonaceous material with

CO2 leads to steady increase of both the micropore and the total pore volume. However, in

contrast to total pore volume after some activation time, the micropore volume reaches its

maximum level, after which it starts to decrease. The observed phenomenon was explained by

merging the small micropores into bigger ones by removal of walls between them. This

conclusion was drawn from the results of volumetric methods using N2 at 77 K and CO2 at

273 K. These methods enabled detailed pore size distributions measurements in the range 0.4-

1.5 and 1.2-50.0 nm respectively. The merging of walls was observed on pore size

distribution as a distinct shift of maximum towards higher pore diameters.

Overall results indicates that N-doped physically activated carbonized polymers might be

used for sorbent synthesis of on demand sorption properties. Moreover, application of pure

polymers as a precursors greatly facilitates understanding of complex phenomena occurring

on carbonaceous sorbents.

0.0

0.5

1.0

1.5

2.0

2.5

3.0

30 130 230

Eth

ene

up

tak

e[m

mo

l/g

]

Temperature [K]

0.0

0.2

0.4

0.6

0.8

1.0

1.2

1.4

1.6

1.8

2.0

30 80 130 180 230

Ca

rbo

n d

ioxid

e u

pta

ke

[mm

ol/

g]

Temperature [K]

(A) (B)

FA-N-1 FA-N-20 FA-N-73 FA-N-88FA-N-0

303 353 403 453 503 303 353 403 453 503


12

New eco-friendly batteries based on carbon nanotubes

W. Ciesielski, D. Kulawik, J. Drabowicz, S. Żarska, A. Ciesielska, K. Kozieł

Institute of Chemistry, Jan Dlugosz University in Czestochowa,

13/15 Armii Krajowej Ave., 42-200 Czestochowa, Poland

The evolution on the energy market of natural resources (ie. crude oil, natural gas, et al.),

and forecasts of energy needs make it necessary to seek new alternative sources of energy.

The biggest hope are biofuels and hydrogen as a fuels of the future.

The interest of new look of the environmental engineering is connection between “green”

chemistry and “good” systems for environment.

Literature searches, based on the use of SciFinder Scholar database showed for the

keywords „catalysed decomposition of biomass”, „biofuels”, "hyrdogen storage" and “green

batteries” more than 5000 literature references, among them 200 publications devoted to

friendly systems for environment.

I would like show main scientific area of our group. These studies concentrate about four

main problem: multi-walled carbon nanotubes, fulerenes and graphene functionalized with

organophosphate anions of selenoacids and tioacids and organic disulfide derivatives as

potential electrode materials in lithium-ion batteries.

The main objective of this project is the development of a new generation of electrodes

that can be used as a link in a new battery friendly for environment. The specific aims of

project are studies on the synthesis, structure determination and the physico-chemical

properties and experiments aimed for use as components analogues of lithium-sulfur batteries

or lithium ion batteries, respectively, organic disulfide compounds, lithium salts of organic

tiooxohetrroacids and selenium organic tiooxohetrroacids. On the other hand a suggestion as

to the possibility of using salt of organophosphate thioacids and organophosphate selenium

thioacids as a component of electrolytes in batteries lithium - ion results from the fact which

show the performance characteristics of ionic liquids. The test materials are new, so they’re

not described group of compounds in the chemical literature, in which the presence of Li ions

creates a favorable possibility of inducing new features and provide the appearance of useful

physicochemical properties of the derivatives obtained upon use as substrates in the chemistry

of the "new materials" (in particular, "electrochemical" ) and new substances for controlling

the electrode processes.

Acknowledgement: This project was financially supported by the National Science Center fund awarded based

on the decision 2015/19/N/ST8/03922.


13

Plasmon enhanced photocurrent generation of Photosystem I coupled with

graphene electrode

D. Kowalska1, M. Szalkowski1, E. Harputlu2, M. Kiliszek3, C.G. Unlu4, K. Wiwatowski1,

J. Kargul3, K. Ocakoglu2, S. Mackowski1

1Instytut Fizyki, Uniwersytet Mikołaja Kopernika w Toruniu, ul. Grudziądzka 5, Toruń, Polska,

e-mail:[email protected] 2Advanced Technology Research and Application Center, Mersin University, Mersin, Turcja 3Centrum Nowych Technologii, Uniwersytet Warszawski, ul. Banacha 2C, Warszawa, Polska

4Department of Biomedical Engineering, Pamukkale University, TR-20070 Denizli, Turcja

Studies of green sources of alternative energy are focused on photosynthetic complexes

applied as building blocks for photosensors, optoelectronic components and photovoltaic

devices. Interaction between metallic nanostructures and pigment-protein complexes can lead

to strong modifications of their optical and electrochemical properties. On the other hand,

graphene is an efficient energy and electron planar acceptor, facilitating surface

functionalization.

In this work we assemble a hybrid nanostructure composed of an oriented monolayer of

Photosystem I from C. merolae on functionalized single layer graphene (SLG) transferred on

the silver islands film (SIF). The orientation was obtained using a novel method via natural

electron donor cytochrome c553. The results were compared to a system, where PSI was

simply physically adsorbed on graphene surface and. Figure 1 illustrates SEM imaged of

composed hybrid nanostructure in the absence of SIF layer.

Fig. 1 Cross-sectional SEM image of the PSI@SLG electrode showing the 85 nm-thick cyt/PSI layer

(schematically shown in the inset) on the SLG/FTO surface. Scale bar is 100 nm.

Fluorescence imaging of presented electrodes with defined orientation of photosynthetic

proteins exhibits homogeneous coverage of PSI on the SLG surface and less efficient energy

transfer compared to a structure, where PSI complexes are physisorbed on graphene surface in

random way. In order to enhance the photocurrent generation in those electrodes, PSI

complexes conjugated to SLG were deposited on SIF substrate. The enhancement of the

optical and electrochemical properties of PSI coupled to the plasmonically active SIF layer is

observed due to increased absorption rates of PSI and , activation of internal energy transfer

pathways. Over a two-fold increase of photocurrents was obtained for SIF – based structures.

The results prove that control of the spatial arrangement of nanoscale components and

implementation of plasmonically active metallic nanostructures are crucial for improving

performance of PSI-based photoelectrodes for energy conversion.

References:

[1] M. Kiliszek, M. Szalkowski, et al. J. Mater. Chem. A 6, 18615 (2018).

Acknowledgement: Research was supported by project DZP/POLTUR-1/50/2016 funded by the National Centre

for Research and Development, and by project DEC-2013/10/E/ST3/00034 funded by the National Science

Centre.


14

Impact of adsorbed gases on the coherence time of paramagnetic centers in

reduced graphene oxide

R. Strzelczyk1, M. Augustyniak-Jabłokow1, K. Tadyszak2, R. Fedaruk3

1Institute of Molecular Physics, Polish Academy of Sciences, Smoluchowski Str. 17, 60-179, Poznań, Poland, 2NanoBioMedical Centre, Adam Mickiewicz University, Ul. Umultowska 85, 61-614, Poznań, Poland

3Institute of Physics, University of Szczecin, Wielkopolska Str. 15, 70-451, Szczecin, Poland


Graphene and graphene-related materials are proposed for quantum computing

applications. One of the problems is construction of qubits (quantum bits) with long spin-spin

relaxation times. The phase memory (coherence) time Tm must be 104 times longer than single

quantum operation. There are ideas of building such qubits from graphene and graphene oxide

quantum dots [1]. The role of qubits can also play slowly relaxing paramagnetic centers.

There are known paramagnetic centers with long spin coherence times at high temperatures

[2], however their integration with electrically conductive graphene matrix is problematic.

The longest spin relaxation times are observed for paramagnetic centers in materials with

very low density of defects, for example in diamonds [3]. In our previous papers [4, 5], we

demonstrated the existence of paramagnetic centers with coherence times in the microsecond

range in graphene oxide which is a very disordered material.

Here, we report our recent results on paramagnetic centers in the hydrothermally reduced

graphene oxide. The product was vacuum dried. After drying a portion of the material was

placed and stored in vacuum sealed tube. The other portion was stored in the open tube, in

contact with atmospheric gases. For this sample we have observed two paramagnetic centers.

One center has short coherence time (0.5 μs). The second center is more interesting and has

the spin coherence time of 3 μs at 200 K (Fig. 1).

Fig. 1. The spin coherence time of paramagnetic centers in hydrothermally reduced graphene oxide.


15

Removal of atmospheric gases from the sample results in the presence of the only one

paramagnetic center with the spin coherence time of order of 1 μs. It is unexpected result, as a

contact of carbon materials with atmospheric paramagnetic O2 molecules results usually in

shortening of the spin relaxation times. However, such result is favorable because qubits

based on this paramagnetic center can be employed under normal conditions.

Literature:

[1] B. Trauzettel, D.V. Bulaev, D. Loss, G. Burkard Nat. Phys. 3(3) (2007) 192

[2] M. Warner, S. Din, I.S. Tupitsyn, G.W. Morley, A.M. Stoneham, J.A. Gardener et all. Nature 503(7477)

(2013) 504.

[3] S. Takahashi, R. Hanson, J. van Tol, M.S. Sherwin, D.D. Awschalom, Phys. Rev. Lett. 101 (2008) 047601 [4] M.A. Augustyniak-Jabłokow, R. Fedaruk, R. Strzelczyk, Ł Majchrzycki, Appl. Magn. Res. 6(50) (2019) 761-

768.

[5] M.A. Augustyniak-Jabłokow, K. Tadyszak, R. Strzelczyk, R. Fedaruk, R. Carmieli, Carbon 152 (2019) 98-

105.


16

Semipermeable membranes based on graphene

P. Kula1, K. Dybowski1, A. Jeziorna1, G. Romaniak1, R. Atraszkiewicz1, Ł. Kołodziejczyk1,

P. Kowalczyk1, D. Nowak1, T. Kaźmierczak2

1) Instytut Inżynierii Materiałowej, Politechnika Łódzka,, ul. Stefanowskiego 1/15, 90-924 Łódź

e-mail: [email protected] 2) Amii Sp. z o.o., ul. Grabińska 23, 92-780 Łódź

Since invention of reverse osmosis (RO) membrane, membrane processes has become

very popular in water treatment due to easy maintenance, height rejection rate, low cost and

good accessibility on the market. Graphene and graphene-based materials are expected to be

key materials in filtration and separation. In this work we present a method of preparation,

structure and properties of semipermeable graphene based membrane. Polysulfone has been

used as a scaffolding. Composite is based on polycrystalline graphene synthetized on liquid

copper (Height Strength Metallurgical Graphene- HSMG®), which was coated with graphene

oxide (GO) to seal defects. Membrane was assembled with pressure-assisted and evaporation-

assisted method and then nanostructured. SEM imaging confirmed the continuity of the

formed HSMG/GO layer, that is free of visible undesirable defects resulting from the transfer

(Fig.1). In this way, filters with a size of 9 cm2 were obtained (Fig.2). Osmotic test conducted

with 0,2 mol NaCl solution proved, that graphene membrane with GO was semipermeable,

because water was transported to solution with higher concentration and at the same time ions

transport was comparable to the one occurring in commercial reverse osmosis membrane.

Membrane flux driven by 4 bar osmotic pressure had value of 100 ml m−2 h−1 bar−1. Graphene

membrane without GO was not semipermeable - after 24 hours NaCl concentration was even

on both sides of the membrane and there was no water flux.

Fig. 1 Graphene membrane after fabrication. SEM image,

AEE mode.

Fig. 2 Graphene/ graphene oxide membrane on

polysulfone. Scale is in cm.

Manufacturing graphene membranes in centimetre scale is challenging. In this work we

presented polysulfone/HSMG graphene/GO-flakes composite as the semipermeable

membrane with very good rejection rate and water flow in osmotic test. In our opinion

proposed manner sealing with nanostructured GO promote its potential in possible water

desalination applications.

References:

[1] S.C. O’Hern et. al, Nano Lett., 15 (5), pp 3254–3260 (2015)

[2] M. Hu et. al, Environ. Sci. Technol., 47 (8), pp 3715–3723 (2013)

[3] S.C. O’Hern et. al, Nano Lett., 14 (3), pp 1234–1241 (2014)

Acknowledgments: The research was performed with the use of EU funds within the framework of the project

no. POIR.04.01.04-00-0089/15, Measure 4.1 “Scientific research and development works”, Sub-measure 4.1.4

“Application projects” of the Smart Growth Operational Programme, 2014-2020, project title: “Composite

materials based on graphene, intended for treatment of water”.


17

Application of noncovalent dye/graphene based material in photocatalysis

A. Lewandowska-Andrałojć1,3, E. Gacka1, D. Larowska1, L. Stobiński2, A. Małolepszy2, M.

Mazurkiewicz-Pawlicka2, B. Marciniak1,3

1Faculty of Chemistry, Adam Mickiewicz University, Uniwersytetu Poznanskiego 8, 61-614, Poznan, Poland 2Faculty of Chemical and Process Engineering, Warsaw University of Technology, Warynskiego 1, 00-645

Warsaw, Poland 3Center for Advanced Technologies, Adam Mickiewicz University, Uniwersytetu Poznanskiego 10, 61-614,

Poznan, Poland

[email protected]

By functionalizing non-covalently dye molecules (porphyrins, xanthenes) to graphene-

based material (GO or RGO), we obtained novel nanomaterials with potential application in

photocatalytic hydrogen production (Figure 1). In our work we synthesized and thoroughly

characterized dye-GO and dye-RGO nanohybrids. Results of FTIR, Raman spectroscopy,

thermogravimetric analysis (TGA), atomic force microscopy (AFM) and elemental analysis

have confirmed successful non-covalent functionalization of graphene sheets with porphyrins.

[1-2] Changes in the absorption spectra proclaim that porphyrin molecules can be efficiently

assembled onto the surfaces of graphene oxide sheets to form stable complexes already in the

ground state. It was found that stronger interaction with GO occurs for cationic porphyrins

and for neutral porphyrins is much weaker. Ultrafast time-resolved transient absorption

spectroscopy clearly demonstrated the occurrence of electron transfer from the photoexcited

porphyrin to GO, indicated by very fast decay of the excited state and the formation of a

porphyrin radical cation.[2] These results are relevant to the use of such systems in

developing energy conversion assemblies.

Figure 1 Schematic hydrogen evolution over dye/graphene oxide/Co cat. under visible light irradiation; D –

sacrificial electron donor.

Under visible irradiation noble-metal-free system EY-RGO-Co(bpy)32+ demonstrated higher

photocatalytic activity than EY-Co(bpy)32+ (Figure 2). RGO material acts as an acceptor and

mediator of the electrons. The recombination of photoexcited charges is greatly retarded, and

the photocatalytic activity increases.


18

Figue 2. The amount of H2 evolved under visible light irradiation: EY-RGO-Co(bpy)3

2+ (black), EY-Co(bpy)32+

(red). Reaction conditions: [EY] = 0.4 mM, [Co(bpy)32+] = 45 µM [RGO] = 1.3 x 10-3 mg ml-1 [TEOA]= 5 vol%,

pH = 10.2.

References

[1] Gacka E., Wojcik A, Mazurkiewicz-Pawlicka M, Malolepszy A., Stobinski L., Kubas A., Hug G.L.,

Marciniak B., Lewandowska-Andralojc A., J. Phys. Chem. C, 123, (2019), 3368

[2] Larowska D., Wojcik A, Mazurkiewicz-Pawlicka M, Malolepszy A., Stobinski L., Marciniak B.,

Lewandowska-Andralojc A., ChemPhysChem, 20, (2019), 1054

Ackonwledgement: This work was supported by the National Science Centre (Grant Number:

2015/19/D/ST5/00682).


19

In vitro biocompatibility of g-C3N4, graphene oxide and reduced graphene

oxide nanosheets – effect of lateral sizes and nanomaterials concentration

M. Aleksandrzak1, M. Jędrzejczak-Silicka2, K. Sielicki1, K. Piotrowska3, E. Mijowska1

1Department of Physicochemistry of Nanomaterials, Faculty of Chemical Technology and Engineering, West

Pomeranian University of Technology, Szczecin, Piastow Ave. 42, 71-065 Szczecin, Poland 2Laboratory of Cytogenetics, West Pomeranian University of Technology, Szczecin,

Klemensa Janickiego 29, 71-270 Szczecin Poland 3Department of Physiology, Pomeranian Medical University, Powstancow Wlkp. 72, 70-111 Szczecin, Poland


Recently, progressing development of nanostructured materials has affected a lot of

materials with very promising potential applications. Hence, determination its toxicity is

being out of step. Some of them can directly impact on environment or, what is more

common, human themselves. Therefore, we have to look closely and with extreme caution to

nanomaterials and their influence on living beings and environment.

Graphene, since its discovery in 2004, has begun extensive studies on two dimensional

materials (2D). Because of its exceptional properties it has attracted enormous scientists

attention and has been researched for different potential applications. Another type of 2D

material, graphitic carbon nitride (gCN), demonstrates unique properties and has been widely

explored, especially for photocatalytic applications.

In this study, biocompatibility of graphene oxide, reduced graphene oxide and graphitic

carbon nitride dispersed in polyethylene glycol has been demonstrated. Wide range of the

nanomaterials concentrations (6.25 – 100 g mL-1) was investigated. Viability of mice

fibroblast cell line (L929) has been determined using cell counting kit-8 (CCK-8) and WST-1

assays. Here, influence of nanomaterials size and concentration was explored. Firstly, when

one compares graphitic carbon nitride with different diameters, the viability of L929 cells

decreased with increase in the lateral sizes. Secondly, independently on the type of the

nanomaterial, the cytotoxicity increased with increase in its concentration. Lastly, graphitic

carbon nitride was found to present the highest biocompatibility to mice fibroblast cells. In

addition, reduced graphene oxide exhibited higher cytotoxicity in comparison with graphene

oxide.

Fig. 1. TEM images of (a) graphene oxide, (b) reduced graphene oxide, (c) the largest (~160 nm), (b) the middle-

size (~20 nm) and the lowest-size gCN (~10 nm).

Podziękowania: Badania zostały sfinansowane przez Narodowe Centrum Nauki w ramach programu Sonata (nr.

2015/19/D/ST5/01920).


20

On-surface synthesis and characterization of nanographenes

R. Zuzak1, M. Szymoński1, S Godlewski1

1 Centre for Nanometer-Scale Science and Advanced Materials, NANOSAM, Faculty of Physics, Astronomy and

Applied Computer Science, Lojasiewicza 11, 30-348 Krakow, Jagiellonian University in Krakow, Poland

Graphene nanostructures are in great attention because of many interesting physical and

chemical properties i.e. adjustable band gap [1] or low energy dissipation [2]. Because of

nanometer sizes, those kinds of nanostructures are very shaped dependent, even small changes

in the topography can drastically change final physical properties. Standard “top-down”

strategies produce single atom defects when the size of the nanostructure is smaller than 10

nm what affect final structure and properties. It is reasonable to search for new experimental

methods which will allow synthesizing defect free new nanographenes (NG). One of the most

promising method is on-surface synthesis where final nanostructures are created by

connecting smaller molecular blocks. Two most known on-surface reactions are Ullmann

coupling and cyclodehydrogenation process used to synthesize defect-free NG [3,4].

Here we will demonstrate a few examples of new nanographenes created and measured

directly at the crystal surface. We will demonstrate a new method for synthesizing long

acenes [5,6]. We will show how by combining in-solution and on-surface synthesis it is

possible to create new graphene nanoflakes [7]. Finally, we will show a new on-surface

reaction where for the first time sp2 graphene nanostructures can be synthesized directly at

non-metallic surface [8]. In the last part of the presentation, new results connected with

covalent organic frameworks (COF) will be demonstrated.

Fig. 1. Hexabenzocoronene molecules synthesized directly at the non-metallic surface (LT-STM image)

References:

[1] Y. Chen et al. ACS Nano 7, 7, 6123-6128 (2013)

[2] Y. Yang et al. PNAS 113 (35) E5098-E5107 (2016)

[3] J. Cai et al. Nature 466, 470–473 (2010)

[4] P. Ruffiex et al. Nature 531, 489–492 (2016)

[5] R. Zuzak et al. ACS Nano 11, 9, 9321-9329 (2017)

[6] R. Zuzak et al. Angew. Chem. Int. Ed. 57,10500–10505 (2018)

[7] R. Zuzak et al. Chem. Commun. 54, 10256-10259 (2018)

[8] M. Kolmer, R. Zuzak et al. Science 363, 57-60 (2019)

Acknowlegment: This research was supported by the National Science Center, Poland (2017/26/E/ST3/00855)


21

Supramolecular complexes of graphene oxide with porphyrins

D. Larowska,1 A. Wójcik,2 M. Mazurkiewicz-Pawlicka,3 A. L. Stobiński,3 A.Kolman,1 A.

Kubas,4 B. Marciniak,1,5 A. Lewandowska-Andrałojć1,5

1Faculty of Chemistry, Adam Mickiewicz University, Poznań, Poland;

2Helmholtz-Zentrum Dresden-Rossendorf, Institute of Ion Beam Physics and Materials Research, Bautzner

Landstraβe 400, 01328 Dresden, Germany;

3Faculty of Chemical and Process Engineering, Warsaw University of Technology, Warsaw, Poland;

4Institute of Physical Chemistry, Polish Academy of Sciences, Kasprzaka 44/52, 01-224 Warsaw, Poland;

5Center for Advanced Technologies, Adam Mickiewicz University, Poznan, Poland


Functionalization of the carbon nanostructures is a rapidly developing research field. The

main aim is to design and obtain a hybrid nanostructure characterized by remarkable

properties of the carbon substrate combined with the strong light absorption of the absorbed

molecules, which have molar coefficients of 105 M-1 cm-1.[1] Among a variety of organic

dyes, porphyrins are well known for their excellent photoactive properties. The availability of

solution-dispersed GO allows for the chemical modification of graphene with various

molecules or nanoparticles via non-covalent or covalent functionalization. These

noncovalently modified graphenes are mainly through molecular interactions, such as

electrostatic interaction, π−π stacking or hydrogen bonding between graphene and organic

molecules. (Fig.1)

Fig.1 Schematic representation of porphyrin-graphene oxide hybrid

In our studies we applied number of meso substituted porphyrins as attractive candidates

to create new graphene based nanohybrids materials. Strength of the interaction between the

porphyrins and graphene oxide was varied by applying different types of porphyrins: anionic,

neutral and cationic. (Fig.2)


22

Fig.2 Structures of: (left) anionic porphyrin – TSPP- 5,10,15,20-tetra-(4-sulfophenyl) porphyrin ; (center)

neutral porphyrin – TAPP- 5,10,15,20-tetra(4-aminophenyl)porphyrin; (right) cationic porphyrin – TMAP-

5,10,15,20-tetra(4trimethylammoniophenyl)porphyrin tetra(p-toluenesulfonate)

The great advantage of the noncovalent-functionalization strategy is that it can combine

the unique properties of the dye and graphene, while it does not disturb the physical properties

of either moiety. In addition, the synthesis is facile. Our graphene-based materials were

prepared by simple mixture of the dye molecules and the dispersed graphene suspension.

Although worldwide interest in the development of porphyrins graphene based materials

resulted in numerous publications, [2-4] there is no or only few comprehensive studies that

would include detailed spectroscopic properties studied by steady-state and time-resolved

technique together with the characterization of the morphology and structure of the graphene

based materials.

In my talk I will present our results in a field of supramolecular graphene oxide –

porphyrin complexes with description of photophysical and photochemical properties of

obtained complexes.

Literature:

[1] K. Ladomenou, M. Natali, E. Iengo, G. Charalampidis, F. Scandola, A. G. Coutsolelos, Coord. Chem. Rev.

2015, 304-305, 38-54.

[2] S. Park; R. S. Ruoff, Nat. Nanotechnol., 2010, 5, 309

[3] D. Chen; H. Feng; J. Li, Chem. Rev., 2012, 112, 6027

[4] S. H. Dave; C. Gong; A. W. Robertson; J. H. Warner; J. C. Grossman, ACS Nano, 2016, 10, 7515

Ackonwledgement: This work was supported by the National Science Centre (Grant Number:

2015/19/D/ST5/00682).


23

Influence of graphene defects on properties of grafted single molecule

magnets – ab initio studies

A. Koshevarnikov1, K. Czelej1,2, M. Zemła1,2, J.A. Majewski1

1Faculty of Physics, University of Warsaw, L. Pasteura 5, 02-693 Warszawa, Poland 2Faculty of Materials Science and Engineering, Warsaw University of Technology,

Wołoska 141, 02-507 Warszawa, Poland

email: [email protected]

The novel hybrid structures involving two-dimensional nano-materials (such as graphene)

and single molecule magnets (SMMs) exhibit intriguing properties and attracted research

activities of few experimental groups. In the future, such systems can constitute a tuneable

array of magnetic nano-objects and lead to novel spin-based technologies, such as spin

quantum memories.

In this communication, we report results of extensive theoretical studies of: (i) the

stability of such hybrid structures, (ii) the nature of interactions between the localized spin in

SMM and 2D material to which the molecule is grafted, and (iii) possibility of tuning the

magnetization of SMMs with light. Our studies are based on the ab initio calculations in the

framework of the density functional theory, employing numerical packages VASP [1] and

SIESTA [2]. In both cases, we pay particular attention to the proper description of the van der

Waals dispersive forces and magnetism. We have considered the certain classes of SMMs,

namely, TM-Phthalocyanines, with TM = V and Fe; Fe(C(SiMe3)3)2 molecules; molecules

with tetrahedrally coordinated Fe and Cr and bound to two doubly deprotonated

bis(methanesulfonamido) benzene ligands. We have investigated their adsorption to

monolayer and bilayer graphene, and graphite. We address also the important issue how the

adhesion and magnetic properties of SMMs are influenced by: (i) structural defects in

graphene, such as vacancies, 5-7 defects, N-dopants, and/or (ii) intentional functionalization

of graphene with simple amines, hydrocarbons, and/or OH groups. For comparison, we have

also studied V-Pc molecule adsorbed at Au(111) surface, and will report on it in another

communication. Our present work sheds light on physical mechanisms of the SMMs

adsorption to half-metallic and metallic surfaces and opens up new prospects for design of

novel spintronic devices.

Figure: The Fe-Pc (left) and Fe(C(SiMe3)3)2 (right) SMMs studied in this paper

References: [1] G. Kresse, J. Furthmuller, Phys. Rev. B 54 (1996) 11169.

[2] J. Soler, E. Artacho, J. D. Gale, A. Garcia, J. Junquera, P. Ordejón, D. Sanchez-Portal, J. Phys. Condens.

Matter 14 (2002) 2745.

Acknowledgements: This research has been supported by the NCN grant OPUS-12, Contract No. UMO-

2016/23/B/ST3/03567.


24

Probing interactions between AlxGa1-xN/GaN axial heterostructure

nanowires and graphene by electroreflectance and contactless transport

J. Kierdaszuk1, M. Tokarczyk1, A. Krajewska2, A. Przewłoka2, W. Kaszub2, M. Sobanska3,

Z.R. Zytkiewicz3, K. Pakuła1, G. Kowalski1, M. Kamińska1, A. Wysmołek1, J. Binder1,

A. Drabińska1

1 Faculty of Physics, University of Warsaw, Pasteura 5, Warsaw, Poland 2 Institute of Electronic Materials Technology, Wólczyńska 133, Warsaw, Poland

3 Institute of Physics, Polish Academy of Sciences, Lotników 32/46, Warsaw, Poland

The presence of local nanogating of graphene deposited on GaN NWs was previously

confirmed by Kelvin Probe Force Microscopy [1]. This observation suggested that the

electromagnetic mechanism might be responsible for the surface-enhanced Raman scattering

in graphene on GaN NWs [2]. In wurtzite GaN a high polarization is present. Recently it has

been shown that NW structure reduces free carrier screening of polarization charges [3]. In

this report we examine the hypothesis that a larger aluminium content in AlGaN NWs should

increase the concentration of the polarization charge induced at NWs tips and furthermore

increase the nanogating effect of graphene. Representative SEM images of graphene

deposited on GaN NWs with Al0.25Ga0.75N caps and a sample scheme are presented in Fig 1.

Fig. 1. SEM images of Al25 sample obtained at: a) 00 tilt, b) 200 tilt, c) samples scheme.

Fig. 2. a) Raman spectra and b) electroreflectance spectra of graphene deposited on axial heterostructure NWs

with different aluminium content.


25

Raman spectroscopy showed spectral enhancement in graphene on AlGaN NWs,

however, no correlation with aluminium content was observed (Fig. 2a) [4]. Moreover, Kelvin

Probe Force Microscopy measurements and detailed analysis of Raman spectra suggested that

value of carrier concentration in graphene is independent of aluminium content. In order to

estimate the value of the electric field induced in the NWs, electroreflectance (ER) technique

was applied. In this experiment an external applied voltage modulates the dielectric function

of the measured material, which is traced by a reflectance measurement performed with

a lock-in detection. The lack of Franz-Keldysh oscillations in the ER signal, which is

characteristic for the low electric field limit (Fig. 2b) casts doubt on whether the NW structure

indeed reduces polarisation charge screening. Therefore, our studies did not allow to clarify if

the electromagnetic mechanism is responsible for the observed SERS in graphene on NWs

Complementary, low temperature microwave contactless transport measurements in ESR

spectrometer were performed (idea was presented in [5]). The observed weak localization

signal is broadened for three-layer graphene deposited on AlN NWs comparing to GaN NWs

due to a reduction of coherence scattering length from about 680 nm to 470 nm (Fig. 3a).

A similar effect for two-layer graphene is observed. However, values of coherence length for

three-layer graphene are slightly lower than for two-layer graphene. A possible explanation

for this observation are interlayer interactions between electrons in the subsequent graphene

layers. An analysis of the temperature dependence of the coherence scattering length shows

two scattering components (Fig. 3b). First – a temperature dependent scattering in the ballistic

regime and the second one – independent on temperature. Therefore, despite of charge

screening still present, interaction with AlGaN NWs affects the properties of graphene

measured by microwave contactless transport.

Fig. 3. a) weak localization signal of 3L graphene on AlxGa1-xN NWs and b) temperature dependence of

coherence scattering length.

References:

[1] Kierdaszuk J., et al., Carbon 128, 70-77 (2018),

[2] Kierdaszuk J., et al., PRB 92, 195403 (2015),

[3] Jamond N., et al., Nanotechnology 27, 32, 325403 (2016),

[4] Kierdaszuk J., et al., Applied Surface Science 475, 559-564 (2019),

[5] Drabińska A., et al., PRB 86, 045421 (2012).

Acknowledgements: The research was partially supported by the Polish Ministry of Science and Higher

Education for years 2015–2019 as a research grant “Diamentowy Grant No. DI2014 015744.”


26

Transport properties of graphene oxide thin films during reduction process

M. Świniarski*, A. Wróblewska, K. Czerniak-Łosiewicz, J. Judek

Faculty of Physics, Warsaw University of Technology, Koszykowa 75, 00-662 Warsaw

*e-mail: [email protected]

Graphene oxide (GO) is a highly oxygen decorated graphene sheet obtained from

chemical oxidation of graphite. GO sheets have interesting properties like good solubility in

water/alcohol solutions and easy reduction to reduced graphene oxide (rGO) [1]. Reduction of

graphene oxide sheets is usually performed to restore the graphene properties. Because of the

complexity of the process, it is hard to remove all functional groups and obtain pure

continuous graphene sheets [2]. Nevertheless, where the unique graphene properties are not

the crucial factor in favor of mass production of conductive graphene flakes, the GO is perfect

to use. The aim of reduction process is usually to change nonconductive GO into conductive

rGO material [3]. Thus, understanding how transport properties change during reduction

process is the objective of this work. We have decided to investigate popular thermal

reduction [4] and rare electron beam irradiation [5].

One of the measurements were performed using in-situ monitoring of sheet resistance

during annealing in different temperatures (Figure 1 a). Additionally, the theoretical model

based on generalized activation energy was proposed, in order to get the value of thermal

reduction process activation energy, which is equal to 0.95 eV (Figure 1 b). The transport

measurements suggest that the two-dimensional variable range hopping (2D – VRH) is

predominant transport model [6].

Figure 1 In-situ electrical measurements results obtained for five annealing temperatures of thin GO layers. The

solid line represents fitting by proposed model. (b) Plot of process rate to get the value of process activation

energy.


27

Second measurements were performed by monitoring the current flow through devices

during electron beam irradiation. This method allows to trim the device to the desired

resistance level (Figure 2 a). The measurements focused also on electron beam reduction

stability, which is the key factor in any production process involving graphene oxide

reduction.

Figure 2. (a) Plot of monitored current during electron irradiation. The measurement clearly show that reduction

can be stopped immiedietly after switchin beam off. (b) and (c) represents SEM pictures of one of devices before

and after reduction process, respectively.

References:

[1] S. Pei and H.-M. M. Cheng, Carbon N. Y., vol. 50, no. 9, pp. 3210–3228, Aug. 2012.

[2] M. Acik et al., J. Phys. Chem. C, vol. 115, no. 40, pp. 19761–19781, Oct. 2011.

[3] G. Eda, C. Mattevi, H. Yamaguchi, H. Kim, and M. Chhowalla, J. Phys. Chem. C, vol. 113, no. 35, pp.

15768–15771, Sep. 2009.

[4] I. Jung, D. A. Dikin, R. D. Piner, and R. S. Ruoff, Nano Lett., vol. 8, no. 12, pp. 4283–4287, 2008.

[5] G. Gonçalves et al., Carbon N. Y., vol. 129, pp. 63–75, Apr. 2018.

[6] M. Świniarski, W. Anna, A. Dużyńska, M. Zdrojek, and J. Judek, submitted.

Acknowledgements:: This work was supported by the National Centre for Research and Development within the

project: LIDER/180/L-6/14/NCBR/2015 – „Innowacyjne przyrządy nano-opto-elektroniczne na bazie kryształów

2D”. This work was supported by the National Centre for Research and Development within the project:

TECHMATSTRATEG1/347012/3/NCBR/2017


28

Tuning the cytotoxicity of Ti3C2 (MXene) flakes by post-delamination

surface modifications

A. M. Jastrzębska1a, A. Szuplewska2, A. Rozmysłowska-Wojciechowska1, S. Poźniak1, M.

Chudy2, A. Olszyna1, B. Scheibe3, V. Natu4, M. W. Barsoum4

1Warsaw University of Technology, Wołoska 141, 02-507 Warsaw 2 Warsaw University of Technology, Noakowskiego 3, 00-664 Warsaw

3NanoBioMedical Centre, Adam Mickiewicz University, Umultowska 85, 61-614 Poznań 4 Drexel University, Philadelphia, PA, 19104

ae-mail: [email protected]

The specific features of two-dimensional (2D) nanomaterials such as their high degree of

morphological anisotropy, specific chemical functionalities, and unique surface charges

define their biological properties. One of the newest families of 2D material labeled

‘MXenes’ has been extensively studied in this context [1, 2]. Specifically, the name ‘MXene’

reflects the layered stoichiometry of their parent MAX phases i.e., Mn+1AXn, where: n = 1, 2,

and 3, M is an early transition metal of the periodic table of elements, A is an element from A

group, and X relates to carbon and/or nitrogen atom. After acidic etching of A element, the

MXene with a chemical formula of Mn+1Xn is obtained [3].

The specific bio-action of MXenes has boosted intensive research on their application in

nanomedicine [1]. However, despite all the above mentioned and other intensive studies on

the medical and other biological-related applications of Ti3C2 MXene, substantial knowledge

of the mechanisms that are responsible for the observed specific bio-effects related to its

pristine and/or oxidized surfaces is still far from being satisfactory. Here we present the

insight into the mechanism of toxicity in vitro of the 2D Ti3C2 MXene. The most important

results of this work are that using simple, inexpensive, post-delamination treatments, such as

ultrasonication or mild thermal oxidation it is possible to ‘tune’ the cytotoxicity of the Ti3C2Tz

flakes. Clearly, sonication of the Ti3C2Tz flakes, or sonication followed by mild oxidation in

the water at 60 °C, renders them selectively toxic to cancer cells as compared to non-

malignant ones. It relates to the appearance of superficial titanium (III) oxide (Ti2O3) layer

corresponding to the type of post-treatment. The presence of surface-Ti2O3 also results in a

noticeably higher generation of oxidative stress compared to the pristine 2D Ti3C2. Our

findings give evidence that the sonication and thermal treatments were successful in changing

the nature of the surface terminations on the Ti3C2Tz surfaces. This study makes a significant

contribution to the future rationalized surface-management of 2D Ti3C2 MXene as well as

encourages new rationalized applications in biotechnology and nanomedicine.

Literature:

[1] Lin H, Chen Y, Adv. Sci. 5 (2018) 1800518

[2] Jastrzębska A M, Szuplewska A, Wojciechowski T, Chudy M, Ziemkowska W, Chlubny L, Rozmysłowska

A, Olszyna A, J. Hazard. Mater. 339 (2017) 1-8.

[3] Naguib M, Kurtoglu M, Presser V, Lu J, Niu J, Heon M, Hultman L, Gogotsi Y, Barsoum M W, Adv. Mater.

23 (2011) 4248-4253.

Acknowledgments: The study was accomplished thanks to the funds allotted by the National Science Centre,

within the framework of the research project ‘SONATA BIS 7’ no. UMO-2017/26/E/ST8/01073 (in the frame of

materials characterization, and biological studies) as well as project ‘SONATA 7’ no.

UMO-2014/13/D/ST5/02824 (in the frame of synthesis of starting material).


29

Extraordinary Zoo of 2D materials and accessing their unique properties in

state-of the-art dispersions via Liquid Phase Exfoliation

B.M. Szydłowska1,2, W. Blau2, J.N. Coleman2, C.Backes1

Heidelberg Universitat, Applied Physical Chemistry, Im Neuenheimer Feld 253, 69115 Heidelberg, Germany

Trinity College Dublin, School of Physics & CRANN, College Green, Dublin 2, Ireland


Since the Graphene discovery and its introduction as a wonder material followed by

Nobel prize awarded in 2010, graphene has attracted scientific community around the world.

Interest was focused not only on exploring graphene intrinsic properties but also its possible

use in real life applications. The Graphene success sparked a question to reach out beyond the

its carbon-based structure. By now, we know that there are more than 5000 layered materials

and nearly 3000 of them can be potentially exfoliated. Such a Zoo of materials where each

one is an individual species gives an opportunity to selectively explore ones with expected

and desired properties.

Uniqueness of layered materials comes from the possibility to thin them down layer by

layer and finally reach few-, bi- and monolayer regime. Only then so called 2D materials

dramatically change their properties while compared to revisited bulk counterparts. In a new

form they represent groups of semiconductors, metals or insulators which are namely three

main building blocks of electronics and have a potential to boost the new era of

nanoelectronics. The possibility to implement 2D materials in a range of new generation

electronics accelerated research on 2D structures and created a need of reliable method to

access, tune and control desired properties.

One of the answers to this challenge is Liquid Phase Exfoliation[1]. It facilitates large

scale isolation of monolayers of 2D materials with precise control of size, shape, composition

and number of layers providing dispersions populated with high quality single and few

layers[2]. 2D structures in form of dispersions offers not only an ease of characterization but a

possibility of further postprocessing; widely opening door to applications in gas sensing,

printed electronics, photonics, flexible devices as well as scoping its route in drug targeting

and medical treatments[3].

The ZOO of existent 2D materials pleases us with an exciting playground filled with

adventures which might be beyond our comprehension and are left only to the capacity of

human imagination!

References:

[1] C. Backes, B.M. Szydlowska et al., ACS Nano, vol. 10, no. 1, pp. 1589-601, Jan 26 2016, doi:

10.1021/acsnano.5b07228.

[2] A. Harvey, B.M. Szydłowska et al., Nature Communication, vol. 9, no. 1, p. 4553, Nov 1 2018, doi:

10.1038/s41467-018-07005-3.

[3] B.M. Szydłowska, B. Tywoniuk et al., ACS Photonics, vol. 5, no. 9, pp. 3608-3612, 2018, doi:

10.1021/acsphotonics.8b00469.


30

Upconverted electroluminescence in van der Waals heterostructures

J. Binder1,2, J. Howarth3,4, F. Withers5, M.R. Molas1,2, T. Taniguchi6, K. Watanabe6,

C. Faugeras1, A. Wysmolek2, M. Danovich 3,4, V.I. Fal’ko 3,4,7, A.K. Geim3,4, K.S.

Novoselov3,4, M. Potemski1,2, A. Kozikov3,4

1 Laboratoire National des Champs Magnetiques Intenses, CNRS-UGA-UPS-INSA-EMFL,

25 Rue des Martyrs, 38042 Grenoble, France 2 Faculty of Physics, University of Warsaw, ul. Pasteura 5, 02-093 Warsaw, Poland

3 School of Physics and Astronomy, University of Manchester, Oxford Road, Manchester M13 9PL, UK 4 National Graphene Institute, University of Manchester, Oxford Road, Manchester, M13 9PL, UK

5 Centre for Graphene Science, College of Engineering, Mathematics and Physical Sciences,

University of Exeter, Exeter EX4 4QF, UK 6 National Institute for Materials Science, 1-1 Namiki, Tsukuba 305-0044, Japan

7 Henry Royce Institute for Advanced Materials, M13 9PL, Manchester, UK


The extensive research on graphene that started more than a decade ago gave rise to a

new vibrant field of research in condensed matter physics, dedicated to so called two-

dimensional crystals. The portfolio of available materials includes a large variety of

insulating, semiconducting as well as metallic materials, which are currently being intensively

studied. The recently introduced concept of so called van der Waals (vdW) heterostructures

[1,2], for which one places many two-dimensional crystals on top of each other opens up an

even larger playground for applications and basic studies. The structures are called van der

Waals, since there are no covalent bonds between different crystals in the out-of plane

direction leaving only van der Waals interaction between different layers.

In this work we present optoelectronic measurements of electrically-driven light emitting

vdW heterostructures based on MoS2 and WSe2 (see Fig.1a for an optical microscope image

of a typical structure).

Figure 1. (a) Optical microscope image of an electrically contacted vdW heterostructure. The edges of the

different layers are outlined and the layers are labelled correspondingly. (b) EL as a function of bias voltage.

An emission at 1.9 eV (1.7 eV) can be clearly observed for bias voltages (Vb) as low as 1.3 V. From [3].

These structures allowed us to unveil the electroluminescence (EL) signal of an

MoS2/WSe2 interlayer exciton (IX), for which the electron is located in MoS2 and the hole in

WSe2 (Fig.1b). Surprisingly an emission at energies of around 1.9 eV (≈ 650 nm) can be

observed at bias voltages as low as 1.3 V (Fig.1b). Normally, one would expect that the

applied voltage roughly corresponds to the energy of the emitted photons. The difference of

about 0.6 eV constitutes hence a remarkable energetic upconversion. This effect was

explained with an excitonic Auger effect [3]. In this picture one interlayer exciton (which is

indirect in real and momentum space) recombines non-radiatively and transfers the energy


31

and momentum to another interlayer exciton that can then give rise to the characteristic

observed intralayer emission of MoS2 and WSe2.

The findings of this work are important in terms of future light emitting device

engineering as well as for future attempts towards the observation of fundamental phenomena

like superfluidity or Bose-Einstein condensation of interlayer excitons in van der Waals

heterostructures.

References:

[1] A. K. Geim, I. V. Grigorieva, Nature 499, 419 (2013)

[2] J. Binder et al., Nano Letters 17, 1425−1430 (2017)

[3] J. Binder et al., Nature Communications, 10:2335 (2019)

Acknowledgements: This work was supported by the EC-FET European Graphene Flagship (no. 785219), the

ATOMOPTO project (TEAM programme of the Foundation for Polish Science co-financed by the EU within the

ERDFund), the European Research Council (Synergy Grant Hetero2D), the Royal Society (UK), the Royal

Academy of Engineering (UK), the Engineering and Physical Sciences Research Council (UK) grants

EP/N010345/1, EP/S019367/1, EP/P026850/1, the US Army Research Office (W911NF-16-1-0279), the

Elemental Strategy Initiative conducted by the MEXT, Japan and the CREST (JPMJCR15F3), JST.


32

Lateral superlattices of graphene and boron nitride

A. Jamróz, J.A. Majewski

Faculty of Physics, University of Warsaw, L. Pasteura 5, 02-693 Warszawa, Poland


Vertical, or van der Waals, and lateral heterostructures of graphene (GR) and hexagonal

boron nitride (h-BN) attracted recently considerable research interest, partly owing to the

hope for fine-tuning of materials’ properties. Therefore, various growth techniques of such

hybrid structures have been developed that allow for fabrication of hybrid h-BN and GR

structures in various stacking topologies. For example, it was possible to grow GR grains over

the h-BN substrate [1] or incorporate laterally h-BN flakes into the GR matrix [2]. All these

hybrid structures could induce the design of novel devices, provided one understands the

relation between structure and properties.

Here, we present extensive study of four types of structures with GR or h-BN as the

matrix: (i) GR dots incorporated into h-BN, (ii) GR dots placed over the h-BN, (iii) h-BN dots

incorporated laterally into GR matrix, and (iv) h-BN dots over the GR layer. We consider dots

of nano size with triangular, hexagonal, and circular shape organized either in ordered lattice

or exhibiting disordered lateral arrangement. Our studies of electronic structure, optical

properties, and electrical properties are based on multi-scale modelling involving ab initio

calculations in the framework of density functional theory (DFT), density functional tight-

binding (DFTB), empirical tight-binding method, and valence force field approach for

geometry optimization. The DFT calculations are employed for small test systems and

provide the parameters in the empirical schemes. We use T-B scheme to determine transport

electric properties of the systems studied. Altogether, our investigations establish valuable

relation between properties and structure that could facilitate the design of future devices

based on these systems.

References: [1] N. Mishra et al., Carbon 96, 497 (2016).

[2] Jun Hua Meng et al., Nanoscale 38 (2015).


2016/23/B/ST3/03567.


33

Theoretical studies of the optical properties of MnPS3 – a 2D magnetic

material

M. Birowska1, J. Kunstmann2

1University of Warsaw, Faculty of Physics, Pasteura 5, 02-093 Warsaw, Poland 2Department of Chemistry and Food Chemistry TU Dresden, 01062 Dresden, German

Atomically thin, magnetic materials have recently gained a lot of attention in the field of

two-dimensional (2D) materials [1]. Single magnetic layers with critical temperature above

room-temperature are extremely attractive for fundamental studies and could potentially be

the basis for a new class of information storage.

Probing the magnetic order of the 2D systems by conventional experimental means is

very challenging. However, it is well known, that even in the single layer limit,

semiconducting two-dimensional materials strongly absorb light. Therefore, optical

spectroscopy is a good method for their characterization.

In order to shed light on the intriguing phenomena of 2D magnetism, we present

theoretical investigations of the optical properties of the layered material MnPS3, which is

one important example from the large family of transition metal phosphorus trisulfide

(MPS3)[2].

Our study reveals, that the interband absorption spectrum, which is proportional to the

imaginary part of the dielectric function, is very similar for different possible magnetic order

of MnPS3. On the other hand, the calculated effective masses of electrons and holes exhibit

an anisotropic behaviour and they do depend on the magnetic order. Aforementioned

properties are reflected in the binding energy of excitons in the studied systems. In addition,

our studies reveal that the Hubbard correction (U) in the DFT+U approach can have a crucial

impact on the prediction of the optical and electronic properties of the investigated structures.

References: [1] M. Gibertini et al., Nat.Nanot. vol. 14, p. 408 (2019).

[2] M. Evain et al., J. of Solid State Chem. vol. 7, p. 244 (1987).

Acknowledgments: MB is funded by the NCN grant no. UMO-2016/23/D/ST3/03446. We thank Gotthard Seifert

(TU Dresden, Germany), Kai Trepte (TU Dresden, Germany) and Zakhar Popov (MISIS, Russia) for helpful

discussions.


34

Theoretical studies of mixed phosphorus trichalcogenides

A. Jankowska, M. Birowska

University of Warsaw, Faculty of Physics, Pasteura 5, 02-093 Warsaw, Poland

The metal phosphorus trichalcogenides (MPX3) are the van der Waals layered materials,

which have been widely studied in the bulk form [1]. Since the graphene has been

successfully exfoliated, atomically-thin layered materials have captured great attention of the

scientific community, due to the wide range of unique properties not observed in the bulk

counterparts. The 2D metal phosphorus trichalcogenides are of special note in future magnetic

and spintronic device applications. In addition, mixed compositions of metallic cations (M)

can result in in enhancement of properties e.g. better electrocatalytic performance and water

splitting has been previously observed for CoNiPS3 material [2]. Hence, the potential

applications of MPX3 could be extended.

In present study, we present the results of extensive first principles calculations of the

mixed MnxNi1-xPS3 systems. Our studies are based on the ab initio calculations in the

framework of the density functional theory (DFT), with the generalized gradient

approximation with U correction (GGA+U) for the exchange-correlation density functional,

and the weak van der Waals forces included, as implemented in the numerical package VASP.

The structural, energetic and magnetic properties of MnxNi1-xPS3 monolayers for different

metallic compositions x, and different arrangement of spins on the manganese and nickel

atoms will be presented, and compared to NiPS3 and MnPS3 monolayers and bulk systems.

References: [1] R. Brec, Solid State lonics 22, 1986, 3.

[2] Q. Liang et al., Adv. Funct. Mater. 28, 2018, 1805075.

Acknowledgments: This research has been supported by the National Science Centre grant no. UMO-

2016/23/D/ST3/03446. Access to computing facilities of PL-Grid Polish Infrastructure for Supporting

Computational Science in the European Research Space and of the Interdisciplinary Center of Modelling (ICM),

University of Warsaw is gratefully acknowledged.


35

Theoretical studies of van der Waals heterostructure NiPS3/graphene

T. Necio, M. Birowska

University of Warsaw, Faculty of Physics, Pasteura 5, 02-093 Warsaw, Poland

Two-dimensional (2D) materials are widely studied since the discovery of the graphene

layer in 2004. The vertical stacking of the 2D materials opens a way for the new class of

materials known as the van der Waals structures [1], in which the properties originating from

the individual layers can be significantly improved. In addition, stacking the 2D magnetic

crystals with different orientations might result in a different magnetic order as well as of the

new physical phenomena.

In this communication, we study the impact of the graphene substrate on the properties of

the antiferromagnetic NiPS3 material, in the framework of the density functional theory

(DFT) within the DFT+U approach, and inclusion of the weak van der Waals forces via the

Grimme method. The NiPS3 layered crystal is one important example from the family of

transition metal phosphorus trisulfide compounds [4] (MPX3 where M = Mn, Fe, Ni; X =S,

Se), The MPX3 family has emerged to be a platform to explore the phenomena of 2D

magnetism. In the present work various properties of the freestanding monolayer of NiPS3,

and the monolayer of the NiPS3 vertically stacked on the graphene will be discussed and

compared. The results of the different mutual orientations of the NiPS3 and graphene layers

will be presented from the point of view the differences in electronic structure and optical

spectrum of NiPS3.

References: [1] A.K. Geim and I. V. Grigorieva, Nature 499, 419-425 (2013).

Acknowledgments: This research has been supported by the National Science Centre grant no. UMO-

2016/23/D/ST3/03446. Access to computing facilities of PL-Grid Polish Infrastructure for Supporting

Computational Science in the European Research Space and of the Interdisciplinary Center of Modelling (ICM),

University of Warsaw is gratefully acknowledged.


36

Functionalized exfoliated boron nitride nano-flakes – in vivo and in vitro

study

M. Trukawka1, E. Czarniewska2, L. Mrówczyńska3, M. Jędrzejczak-Silicka4, P. Nowicki2, E.

Mijowska1

1 Nanomaterials Physicochemistry Department, West Pomeranian University of Technology,

Piastów Avenue str. 45, 70–311 Szczecin, Poland 2Department of Animal Physiology and Developmental Biology, Adam Mickiewicz University, Institute of

Experimental Biology, 61-614 Poznań, Poland 3Department of Cell Biology, Adam Mickiewicz University, Institute of Experimental Biology,

61-614 Poznań, Poland 4Laboratory of Cytogenetics, West Pomeranian University of Technology,

Klemensa Janickiego str. 29, 71-270 Szczecin Poland


Hexagonal boron nitride is also known as so called white graphene. This is due to 2D

layered structure similar to graphene. Focused interest in many application such as cosmetics,

dental cements, ceramics and medicine [1, 2, 3]. Therefore, it of high importance to reveal the

influence of this material on the cell lines and on living organisms.

The aim of this contribution was to induce the hydrophilicity of the h-BN in aqueous

environment and then investigate whether the obtained nanoflakes are cytotoxic. To induce

the water solubility of the h-BN nanomaterial, first h-BN was exfoliated and secondly

functionalized with hydroxyl groups (h-BN-OH). The structure of the material was detected

by transmission electron microscopy, scanning electron microscopy and atomic force

microscopy. The functionalization with hydroxyl groups was observed in spectra obtained via

infrared spectroscopy. The dispersion stability was confirmed by a UV-Vis spectrometer.

Next, using various in vivo and in vitro models, we studied the effect of the h-BN-OH

nanoflakes (h-BN-OH-n) on miscellaneous cellular models: insect haemocytes, human

erythrocytes and mouse fibroblasts (the L929 cell line) to detect the possible adverse short-

and long-term effects.

This report shows that the functionalization of the h-BN by hydroxyl groups significantly

increased the hydrophilicity of this material, enabling its stable dispersion in aqueous

solutions in the form of nanoflakes. We confirmed that the nanoflake dispersion was stable

and that the size of h-BN-OH-n was suitable to penetrate through a tight biological barrier as

the beetle's cuticle. The in vivo study on insect haemocytes and the in vitro study on mouse

L929 cells and human erythrocytes showed that this nanomaterial exhibits low cytotoxicity,

which indicates its poor reactivity with biological systems.

References:

[1] Chen X, Wu P, Rousseas M, Okawa D, Gartner Z, Zettl A, Bertozzi CR. J Am Chem Soc 2009 131:890-91.

[2] Jędrzejczak-Silicka M, Trukawka M, Dudziak M, Piotrowska K, Mijowska E. Hexagonal Nanomaterials

2018 8: 605-627

[3] Emanet M, Sen O, Çulha M. Nanomedicine 2017 12: 797–810

Acknowledgments: This work was supported by the National Science Centre [NCN]: Grant number

2016/21/N/ST8/02397 and Grant number 2018/02/X/NZ3/00161


37

Polarization resolved Raman spectroscopy of 1T-TaS2

M. Furman1, E.M. Łacińska1, J. Binder1, I. Lutsyk2, Z. Klusek2, R. Stępniewski1,

A. Wysmołek1

1 Faculty of Physics, University of Warsaw, Pasteura 5, 02-093 Warsaw, Poland 2Faculty of Physics, University of Łódź, Pomorska 149/153, 90-236 Łódź, Poland

Transition-metal dichalcogenides (TMDs) belong to the intensively studied class of two-

dimensional (2D) materials. This family includes tantalum disulphide (TaS2) - characterized

by four successive phase transitions of the first type associated with charge density wave

(CDW) phases [1] and a relatively high value of spin-orbit coupling [2]. At high temperatures

the material is metallic, whereas at low temperatures (below around 200 K) a periodic lattice

distortion occurs, leading to superlattice formation and a bandgap opening.

Raman spectroscopy is a fast and non-invasive method, widely used in transition-metal

dichalcogenides research. Polarization dependent Raman measurements allow to determine

the symmetry of active vibrations [3] appearing in the 1T-TaS2 structure at low temperatures

in the commensurate charge density wave (CDW) phase, where more intense, narrow peaks

associated with the periodic deformations of the crystal lattice are observed in the Raman

spectrum.

In this communication, we present polarisation resolved Raman spectroscopy of 1T-TaS2

in the commensurate CDW phase. Experiments were performed using 532 nm and 633 nm

excitation wavelengths, as a function of polarization angle beteen scattered and excited light.

Figure 1 shows exemplary results for several Raman lines measured using 532 nm excitation

at 5 K. Interestingly, the observed maxima in intensity show different polarization directions,

with respect to the polarization of the exciting laser light.

Figure 1. Polar plots of the intensity of selected Raman lines as a function of polarization angle between

scattered and excited light, obtained at 5 K using 532 nm excitation wavelength.

Interstingly the observed angle polarisation characteristics depend on the excitation

wavelengths. The obtained results will be disscussed in terms of resonant Raman scattering

which provide new information about the band structure of 1T-TaS2, in particular about the

symmetry of the valence and conductivity band involved in the inelastic light scattering

process.

References:

[1] M. Yoshida et al., Sci. Adv. 2015;1:1500606

[2] K. Rossnagel, N. V. Smith., Physical Review B 73, 073106 (2006)

[3] Oliver R. Albertini et al., Physical Review B 93, 214109 (2016)

Acknowledgements: This work was partially supported by the National Science Centre of Poland (NCN) grant

No. 2015/19/B/ST3/03142.


38

How to snapshot a phase transition? Thermoelectric properties of 1T-TaS2

K. Ludwiczak1, E. Łacińska1, J. Binder1, I. Lutsyk2, M. Rogala2, P. Dąbrowski2, Z. Klusek2,

R. Stępniewski1, A. Wysmołek1

1Faculty of Physics, University of Warsaw, ul. Pasteura 5, 02-093 Warsaw, Poland 2Faculty of Physics and Applied Informatics, University of Lodz, Pomorska 149/153, 90-236 Lodz, Poland,

e-mail:[email protected]

Tantalum disulfide (1T-TaS2) is a representative of the family of transition metal

dichalcogenides, which are materials that in the few-layer limit exhibit a completely different

behaviour than in the bulk form [1]. These interesting properties make them a great candidate

for novel optoelectronic device applications.

Despite being studied in bulk form already decades ago, the research on ultrathin 1T-TaS2

is still in its early stages. 1T-TaS2 exhibits an extraordinary rich phase diagram connected to

the appearance of charge density waves. In the low-temperature regime the material changes

its structure and forms a superlattice which leads to a temperature dependent metal-insulator

phase transition. Switching between the two phases with a large applied current was recently

reported, indicating the possibility to create novel memory devices [2].

During the phase transition the sign of the majority charge carriers changes, which

strongly affects properties such as the Seebeck and Hall coefficients. Here we present a novel

method to observe such a phase transition. By using spatially resolved voltage measurements,

we gain information about a laser induced thermoelectric effect in a bulk sample of 1T-TaS2.

Sign and magnitude of the measured voltage change as a function of laser illumination

position on the sample. Figures 1(a) and 1(c) depict voltage maps for conducting and

insulating phases. Voltage peaks are inverted due to the change of sign of the majority

carriers.

A precise temperature manoeuvre allows us to “freeze” the state between two different

phases as shown in Figure 1(b). Consecutive measurements proved that such a metastable

state is long-lived. Repeating the temperature manoeuvre allows us to “snapshot” a phase

transition in different states of its nucleation.

Figure 1: Laser-induced thermoelectric voltage maps obtained for (a) low-temperature state, (b) metastable state

during the phase transition (c) high-temperature state.


39

To quantify the respective proportion of each phase we additionally performed Raman

spectroscopy measurements. A careful analysis of the spectra with Principle Component

Analysis (PCA) allowed us to extract the quantitative contribution of each phase needed to

reconstruct the spectra. Based on this Raman analysis we can conclude that both phases must

be present within the size of the laser spot (around 1µm). Moreover, by spatially mapping the

sample we observe that the contributions vary for different spots on the sample.

Our results prove that it is possible to capture a state in between the two phases and that two

distinct phases are present on the sample simultaneously. We hence present a novel method to

manipulate and characterise metastable, long-lived states which opens up new possibilities for

future studies.

Literature:

[1] H. Terrones et al. Scientific Reports 4, 4215 (2014).

[2] M. Yoshida et al. Science Advances 1(9), 2015.

Acknowledgement: The work was financially supported by The National Science Centre (Poland) under Grant

No. 2015/19/B/ST3/0314


40

Photodetectors based on transition metal dichalcogenides

K. Czerniak-Łosiewicz, M. Świniarski, A. P. Gertych, J. Judek

Wydział Fizyki, Politechnika Warszawska, ul. Koszykowa 75, 00-662 Warszawa


Transition metal dichalcogenides (TMDs) have emerged as promising materials in the

field of optoelectronics. The presence of the direct bandgap in the monolayer, fast and

potentially high responsivity and high light absorption over a wide range of wavelengths

make them excellent materials for applications especially in photodetection. [1,2]

In this work, we prepared photodetectors on CVD grown TMDs on sapphire substrate

using lithographic techniques. We measured photocurrent response to illumination with white

and monochromatic light and further correlate it with TMDs photoluminescence spectra. To

distinguish the influence of production techniques on devices from intrinsic properties of

materials, we measured a series of devices and check their reproducibility.

Our results contribute to a better understanding of the mechanisms of photocurrent

generation in TMDs and show high potential of using these materials in a wide range of

optoelectronic applications.

Figure. 1. a,b) SEM images of prepared devices on MoS2. The devices were created using electron beam

lithography with plasma etching and thermal evaporation of metallic electrodes. c) Photocurrent response of the

sample under illumination as a function of time. The samples give repeatable and reversible response to

illumination under white halogen light. d) Electrical response of the sample under illumination with

monochrome light as a function of wavelength. Dashed lines mark the wavelengths at which we can observe

excitonic transitions in MoS2 samples.

References:

[1] Furchi, M. M., Polyushkin, D. K., Pospischil, A., & Mueller, T. (2014). Nano letters, 14(11), 6165-6170.

[2] Wi, S., Kim, H., Chen, M., Nam, H., Guo, L. J., Meyhofer, E., & Liang, X. (2014). nano , 8 (5), 5270-5281

[3] Steinhoff, A., Kim, J. H., Jahnke, F., Rosner, M., Kim, D. S., Lee, C., ... & Gies, C. (2015). letters, 15(10),

6841-6847.

Acknowledgements: This work was supported by the National Centre for Research and Development within the

project: LIDER/180/L-6/14/NCBR/2015 – „Innowacyjne przyrządy nano-opto-elektroniczne na bazie kryształów

2D”. This work was supported by the National Centre for Research and Development within the project:

TECHMATSTRATEG1/347012/3/NCBR/2017


41

Design and application of g-C3N4 based structures towards photocatalytic

processes

M. Baca*, M. Aleksandrzak, R.J. Kaleńczuk, B. Zielińska

West Pomeranian University of Technology, Szczecin, Faculty of Chemical Technology and Engineering,

Nanomaterials Physicochemistry Department,

Piastow Ave. 45, 70-311Szczecin, Poland

*e-mail: [email protected]

Visible light driven photocatalysis has become a suitable tactics for environmental

pollution prevention and energy depletion. To date, many efforts have been made to develop

photocatalysts with unique properties such as high abundance, low cost and most of all,

extended light absorption range resulting in improved photocatalytic performance [1-2].

Layered materials may be a new era for photocatalysis due to strong interlayer chemical

bonding correlated to weak interlayer interactions. They display high activity both as

individual units and components of hybrid or ternary structures. However, recent researchers

attention has been paid to structure-modulation which enables control of electronic band and

enhanced separation of photogenerated carriers [3-4]. Graphitic carbon nitride has attracted

wide concern since it was invented in 2009. Properties of this layered material exceed most of

other photocatalysts thanks to it can be used in photocatalytic pollutant degradation as well as

photocatalytic hydrogen production through water splitting. Moreover, it has easily tunable

structure. Modifying process conditions such as temperature may introduce defects into the

structure or cause exfoliation and thus effectively extend the light absorption [4-5].

Sensitization with narrow band gap semiconductor suppress charge carriers recombination

and enhance solar energy utilization [3,6].

This study aims to brief presentation of recent progress in the design of novel materials

based on graphitic carbon nitride in various realms such as photocatalytic hydrogen

production and photocatalytic degradation of wastewater pollutants under visible light

irradiation. The physicochemical properties of obtained catalysts were examined using

following techniques: transmission electron microscopy (TEM), scanning electron

microscopy (SEM), Raman spectroscopy, X-ray diffraction (XRD), thermogravimetric

analysis (TGA), atomic force microscopy (AFM). The specific surface area was calculated by

the Brunauer-Emmett-Teller (BET). Finally, the presentation will be rounded up with

concluding remarks and further perspectives of presented structures.

Literature:

[1] Z. Zhao ,Y. Sun, F. Dong, Nanoscale, 7 (2015) 15-37.

[2] G. Capilli, M. Costamagna,F. Sordello, C. Minero, Appl. Catal. B: Environ (2019) 121-131.

[3] Y. Wang, X. Zhao, D. Cao, Y. Wang, Y. Zhu, Appl. Catal. B: Environ. 211 (2017) 79–88.

[4] B. Zhu, J. Zhang, C. Jiang, B. Cheng, J. Yu, Appl. Catal. B: Environ. 207 (2017) 27-34.

[5] Kang, Y., Yang, Y., Yin, L. C., Kang, X., Wang, L., Liu, G., & Cheng, H. M. Adv.Materials, 28(30) (2016) ,

6471-6477.

[6] L. Zubizarreta, J.A.Menendez, J.J. Pis, A. Arenillas, Int J Hydrogen Energy 34 (2009) 3070-3076.

Acknowledgements: We thank National Science Center, Poland (UMO-2016/21/B/ST8/02733)


42

Optical properties of nanocomposites based on various 2D materials in

terahertz regime

K. Żerańska-Chudek, A. Łapińska, A. Siemion, M. Zdrojek

Faculty of Physics, Warsaw University of Technology

Koszykowa 75, 00-662 Warsaw, Poland


During standard operation, electronic devices, such as communication antennas, mobile

phones or personal computers, are due to produce unwanted electromagnetic radiation. The

collective undesired radiation from the electrical instruments worldwide is called the

‘electromagnetic pollution’ and the disturbance caused by this radiation is called

electromagnetic interference (EMI). Electromagnetic interference may influence the operation

of sophisticated electronic devices resulting in malfunctions, data leakage in digital

communication or, if medical equipment is affected, even be of danger to human health.

Due to the rising demand for faster and more efficient electronic devices, the electronics

industry is shifting towards terahertz frequencies. In this context, there is a growing need for

efficient, lightweight and easy to produce packaging for EMI shielding in the terahertz range.

Here, we present a comparative study of basic optical properties in the THz range of

novel polymer composites loaded with various 2D particles – graphene, MXenes (Ti3C2 and

TiC2) and hexagonal boron nitride. We investigate EMI shielding efficiency, absorption

coefficient, the refractive index and complex dielectric function of polymer based composites

in the single terahertz range (0,1—3 THz). Finally we report a series of elastic,

nonconductive, low-reflection polymer composites with poor to high EMI shielding efficiency

(depending on the 2D filler used), and absorption as the main shielding mechanism.

Figure 1. (a) SEM image of graphene/PDMS composite. The cross-section shows random flakes distribution

without any visible percolation paths forming. (b) Picture showing the flexibility of fabricated composites. (c)

Absorption coefficient of fabricated composites.


43

Exfoliation of ultrathin epitaxial layers of boron nitride grown by MOVPE

J. Iwański, J. Binder, K. Pakuła, R. Bożek, R. Stępniewski, A. Wysmołek

Faculty of Physics, University of Warsaw, Pasteura 5, 02 – 093 Warsaw, Poland


Hexagonal boron nitride (h-BN) is an extremely interesting material from the class of

two-dimensional materials. The growing interest in BN also results from the fact that it is an

excellent substrate, as well as insulating barrier material for hybrid structures composed of

graphene, transition metal dichalcogenides and other 2D materials [1]. Moreover, a large

cross section for neutron capture renders BN an outstanding candidate for neutron detectors

[2]. Boron nitride can also be used in quantum cryptography as platform for single photon

emitters [3]. There are plenty of different applications of h-BN and that is why it is crucial to

obtain high quality layers, as large and

as thin as possible.

In this report we show that this goal

can be obtained using Metal Organic

Vapour Phase Epitaxy (MOVPE)

combined with wet exfoliation methods.

It was found that the conditions used

at the initial stage of growth, influencing

the interface with the sapphire substrate,

are crucial for further exfoliation of the

BN layers. With this knowledge, we

show that wet exfoliation in different

aqueous solutions provides the

possibility to transfer continuous

epitaxial BN layers with few layer

thickness on wafer-scale surfaces (see

Fig. 1). The layers obtained using this

method are of high optical and structural

quality and can be suitable for

encapsulation of different 2D materials

as well as a part in Nano-Lego structures

based on various 2D crystals to protect

them against degradation.

References:

[1] J. Binder, et al., NANO LETT.,17, 1425-1430 (2017)

[2] J. Li et al., Instr. and Meth. A 654, 417–420 (2011).

[3] M. Koperski et al., Nanophotonics, 6, 1289-1308, 2017

[4] J. Shim et al., Science, 362, 666 (2018)

Fig. 1 Optical microscope image of an epitaxial BN layer

(grey area in the top right corner) deposited on a sapphire

substrate.


44

Optical and structural characterization of boron nitride grown by MOVPE

A.K. Dąbrowska, M. Tokarczyk, K. Pakuła, G. Kowalski, J. Binder, A. Wysmołek,

R. Stępniewski

Institute of Experimental Physics, Faculty of Physics, University of Warsaw,

Pasteura 5, 02-093 Warsaw, Poland


Boron nitride (BN) is a semiconductor compound from III-V group. The most popular

form is sp2-hybridized BN, consisting of the honeycomb-like planes built from nitrogen and

boron atoms [1]. Such material has an energy gap of about 6 eV [2], being at the same time

a two-dimensional material, whose individual layers can be part of van der Waals

heterostructures [3]. All this makes BN a good candidate for applications such as

optoelectronics in deep ultraviolet (DUV) and electronics in general - also where flexibility

and strength of this material will be useful.

Metal Organic Vapor Phase Epitaxy (MOVPE) allows obtaining material with a large

surface area. In our laboratory boron nitride is grown in two modes – Continuous Flow

Growth (CFG) and Flow-rate Modulated Epitaxy (FME). The main growth parameters that

can be changed are the temperature and the pressure in the reactor, flows of nitrogen

(ammonia) and boron (triethylborane) precursors. Depending on the layout of the process, BN

may occur in one of the three forms: a densely nucleated, polycrystalline material (Fig.1 A), a

material consisting of thin, differently oriented flakes with a large surface area (Fig.1 B) or a

continuous epitaxial layer (Fig.1 C). It very often exhibits the luminescence in the range of

540 - 800 nm, excited by laser light with a wavelength of 532 nm, regardless of the structural

quality. It is related to the presence of the point defects or their complexes in the structure.

Measurements of the Raman effect, X-ray diffraction and scanning electron microscopy are

necessary to examine the crystallographic structure, identify the characteristic vibrations and

determining the aligment of the material to the substrate. All information obtained through

these studies, enriched with process parameters and results of intrinsic photoluminescence

measurements, made it possible to gain control over both the boron nitride structure and the

formation of defects. Results will be presented together with consideration of the nature of

point defects in the boron nitride due to the presence of carbon, hydrogen, excess boron and

nitrogen deficiency.

Fig. 1. Scanning Electron Microscopy images of the surface of the boron nitride grown in different conditions:

A – CFG, low pressure and low ammonia flow, B - CFG, high pressure and high ammonia flow, C – FME.

Literature:

[1] N. Ohba, K. Miwa, N.Nagasako, A. Fukumoto, Phys. Rev. B 63, 115207 (2001)

[2] K. Watanabe, T. Taniguchi, H. Kanda, Phys. Stat. Sol. (a) 201, No. 11, 2561–2565 (2004)

[3] K. S. Novoselov, A. Mishchcenko, A. Carvalho, A.H. Castro Neto ., Science vol. 353, aac9439 (2016)


45

“Real-World” Waste Polymers from Bottles for 2D Porous Carbons in

Supercapacitors

Y. Wen, X.Chen, E. Mijowska

Nanomaterials Physicochemistry Department, Faculty of Chemical Technology and Engineering, West

Pomeranian University of Technology, Szczecin, Piastów Ave. 42, 71-065 Szczecin, Poland.

In recent decades, the ever-increasing generation of waste plastics has created terrible

environmental problems and aggravated energy crisis1. Sustainable development and serious

energy crisis called for appropriate management for a large number of municipal and

industrial waste plastics as well as the development of low-cost, advanced materials for

energy storage2,3. As the promising energy-storage devices, supercapacitors have been widely

applied in memory backup systems, uninterruptible power sources, transportation, and storage

of energy from renewable sources, due to high power density and long cycle life4.

Herein, the “real-world” waste plastics, which consisted of PP from waste woven bags,

PE from waste vessels, PS from waste foam sheets, PET from waste beverage bottles, and

PVC from waste sewage pipes, are transformed into carbon nanosheets (CNSs) on OMMT.

OMMT firstly promotes the degradation of waste plastics and then acts as a template for the

in-situ growth of CNSs from these degradation products. Upon KOH activation, porous CNSs

(PCNSs) with hierarchically porous structure is produced and exhibits superior performances

in supercapacitors. This work not only provides a potential way to recycle mixed waste

plastics, but also puts forward a facile sustainable approach for the large-scale production of

PCNSs as a promising candidate for supercapacitors.

Figure 1. (a) a schematic illustration for the synthesis of PCNSs from “real-world” mixed five-component waste

plastics; (b) SEM and (c) TEM of PCNSs; (d) CV curves, and (e) specific capacitances vs current densities

References:

[1] I. A. Ignatyev, W. Thielemans, B. Vander Beke, ChemSusChem 7 (2014), 1579-1593.

[2] J. G. Wang, F. Y. Kang, B. Q. Wei, Prog. Mater Sci. 74 (2015), 51-124.

[3] Y. Wen, K. Kierzek, X. Chen, J. Gong, J. Liu, R. Niu, E. Mijowska, T. Tang, Waste Manage. (Oxford) 87

(2019), 691-700.

[4] Y. Wen, L. Zhang, J. Liu, X. Wen, X. Chen, J. Ma, T. Tang, E. Mijowska, Nanotechnology 30 (2019),

295703.

46

SESJA POSTEROWA

47

Application of bacterial cellulose produced by Komagataeibacter xylinus as

a cell growth substrate for bovine mammary epithelial cells (MAC-T)

M. Gliźniewicz1, D. Ciecholewska2, M. Jędrzejczak-Silicka1

1Laboratory of Cytogenetics, West Pomeranian University of Technology, Szczecin,

Klemensa Janickiego 29, 71-270 Szczecin, Poland 2Department of Immunology, Microbiology and Physiological Chemistry, West Pomeranian

University of Technology, Szczecin, ul. Al. Piastów 17, 70-315 Szczecin


Bacterial cellulose (BC) is extracellular organic compound synthesized by some types of

bacterial cells. BC is characterized by unique properties such as high purity, high tensile

strength, high water holding ability, high degree of crystallinity [1]. Recently, microbial

cellulose became very popular, due to its good biocompatibility and a great potential to

become popular biomaterial for tissue engineering. BC supports cellular adhesion and

proliferation, thus the BC scaffolds can be promising alternative to widely used polymers in

implants production and dressing used in wound healing therapies [2,3].

The purpose of the presented study was to determine the usability of the bacterial cellulose

obtained through biosynthesis using Komagataeibacter xylinus as a functional substrate for

bovine mammary epithelial cell growth.

The bacterial cellulose (BC) was obtained with the use of Komagataeibacter xylinus

ATCC 5352 strain culture. The K. xylinus was maintained using liquid Hestrin-Schramm (H-

S) and solid H-S-agar media. The biosynthesis of BC was carried out at 28°C temperature for

5 days. The synthesised BC was purified by washing with deionised water and 1% NaOH to

remove bacterial cells. Afterward, cellulose was incubated in PBS for 48 h (with controlled

pH every 24-hour) punched into round-shaped samples (6.35 mm and 15.40 mm diameters)

and incubated in complete DMEM medium for MAC-T cell cultures for additional 24 h.

The bovine mammary epithelial cells (MAC-T) was seeded on bacterial cellulose

substrate placed into 96-well microplates for CCK-8 assay and into 24-well plates for

morphological analysis. The MAC-T cell cultures were maintained in standard culture

conditions at 37°C, 5% CO2 and 95% humidity in complete DMEM with high glucose

concentration (4500 mgmL-1) supplemented with 10% heat-inactivated fetal bovine serum, 2

mM L-glutamine, 1 μgmL-1 insulin, 50 IUmL-1 penicillin and 50 µgmL-1 streptomycin. Cells

were cultured on cellulose substrate for 48 h and 96 h. After incubation period the CCK-8

(Cell Counting Kit-8) analysis was performed to determine relative cell viability of MAC-T

cells. The cell morphology was visualized with a Nikon TS-100 microscope.

Firstly, the viability of MAC-T cells cultured on bacterial cellulose substrate was

determined using the Cell Counting Kit-8 (CCK-8) assay. It was found that after 48-hour

culture the MAC-T cells viability was reduced to 20% vs. control culture (cells cultured on

the polystyrene culture plates). After 96-hour of experimental culture the MAC-T cells

displayed cellular viability reduced to 7% in comparison to control cultures.

Secondly, cellular morphology and distribution of MAC-T cells have been studied using

phase contrast microscopy. The bovine mammary epithelial cells cultured on BC substrate for

48-hour showed limited growth and proliferation (compared to control culture) (Fig. 1C, 1D).

After 48 h of cultures cells did not displayed typical for mammary epithelial cells cobblestone

shape. The MAC-T cells growing in BC surface were predominantly highly rounded and did

not form islets. The bovine mammary epithelial cells maintained for 4 days on BC surface

formed aggregates of circular cells (Fig. 1E, 1F). The growth of cells and proliferation was

also reduced in comparison to control cultures.

48

Fig. 1. Surface morphology of bacterial cellulose –phase contrast images (magnification = 100x) (A) and

(magnification = 400x) (B); morphology and distribution of bovine mammary epithelial cells (MAC-T) control

culture at 48 (C) and 96 h (D); MAC-T cells on the BC at 48 h (D) and 96 h (F) (magnification = 100x).

In summary, it can be concluded that the obtained in this study microbial cellulose did not

support MAC-T cells adhesion and proliferation in contrast to the results obtained from L929

cell cultures maintained on BC scaffold [3].

References:

[1] N. Sanchavanakit, W. Sangrungraungroj, R. Kaomangkolgit, T. Banaprasert, P. Pavasant, M. Phisalaphong,

Biotechnol. Prog. 22 (2006) 1194–1199.

[2] G. Xiong, H. Luo, F. Gu, J. Zhang, D. Hu, Y. Wan, J. Biomater. Nanobiotechnol. 4 (2013) 316-326.

[3] K. Dydak, A. Junka, P. Szymczyk, G. Chodaczek, M. Toporkiewicz, K. Fijałkowski, B. Dudek, M.

Bartoszewicz, PLOS One. 13 (2018) e0205205.

49

A preliminary in vitro study on boron nitride nanocomposites loaded with

10-hydroxycamptothecin on mammalian cells

M. Trukawka1, K. Piotrowska2, M. Jędrzejczak-Silicka3, E. Mijowska1

1Nanomaterials Physicochemistry Department,West Pomeranian University of Technology, Szczecin,

Piastow Avenue 45, 70–311 Szczecin, Poland

e-mail: martyna.barylak @zut.edu.pl 2Department of Physiology, Pomeranian Medical University, Powstancow Wlkp. 72, 70-111 Szczecin, Poland

3Laboratory of Cytogenetics, West Pomeranian University of Technology, Szczecin,

Klemensa Janickiego 29, 71-270 Szczecin, Poland

Hexagonal boron nitride (h-BN) is the 2D layered nanomaterial. In its structure,

alternating boron and nitrogen atoms substitute carbon atoms and the boron and nitrogen

atoms are linked with each other via strong B-N covalent bonds [1-4]. Due to its interesting

physical and chemical properties it can be used in different fields such as electronic,

electrochemical or cosmetic industries [1-4].

Hexagonal boron nitride displays low cytotoxicity and seems to be suitable for wide

biomedical applications [5]. Several biocompatibility studies based on hexagonal boron

nitride nanosheets (h-BN), boron nitride nanotubes (BNNT), hollow boron nitride

nanospheres demonstrate their good biocompatibility and improved hydrophilicity [6-8].

Thus, the aim of the study was to synthesise hexagonal boron nitride nanocomposites loaded

with anticancer drug – 10-hydroxycamptothecin – and evaluate their biocompatibility on human

breast adenocarcinoma cells.

Two nanocomposites were tested: hexagonal boron nitride functionalized with hydroxyl

groups (h-BN-OH) and hexagonal boron nitride functionalized with gold nanoparticles (h-

BN-Au). In order to synthesize nanocomposites, commercially available hexagonal boron

nitride was exfoliated by combined chemical and physical methods. The size of the obtained

flakes ranged from 300 to 900 nm, while their thickness was about 5 nm. The gold

nanoparticles had a size of from 6 to 20 nm, with majority of nanoparticles with size ca. 15

nm. Then 10-hydroxycamptothecin was attached chemically to such prepared structures. The

obtained nanocomposites with drug had been biologically tested.

The human breast adenocarcinoma cells (MCF-7) was seeded into 96-well microplates for

CCK-8, LDH and NRU assays and on glass coverslips in 6-well plates for cellular uptake

analysis(in standard culture conditions at 37°C, 5% CO2 and 95% humidity). Cells were

cultured 24-hour incomplete DMEM supplemented with 10% heat-inactivated fetal bovine

serum, 2 mM L-glutamine and 50 IUmL-1 penicillin and 50 µgmL-1 streptomycin. After 24-

hour incubation period, to novel boron nitride nanocomposites (h-BN-OH and h-BN-Au)

loaded with 10-hydroxycamptothecin was added to the cell culture at final concentrations of

3.125, 6.25, 10.0, 12.5, 25.0, 50.0, 100.0, 200.0 µgml-1 in the culture medium and cells were

incubated with the nanocomposites for 72 h.

At first CCK-8 (Cell Counting Kit-8) analysis was performed to determine relative cell

viability of MCF-7 cells after 72-hour exposition to nanocomposites. Secondly, the LDH

CytoTox 96® Non-Radioactive Cytotoxicity Assay was used to determine cell membrane

integrity. Finally, the In Vitro Toxicology Assay Kit based on neutral red dye was used to

detect cell ability to incorporate NR dye into lysosomes.

For uptake analysis MCF-7 cells were incubated with the nanocomposites labeled with

FITC was examined under the confocal microscope. For cell nuclei localization DAPI stain

was used.

50

The analysis of MCF-7 cell cultures incubated with the nanocomposites loaded with 10-

hydroxycaptothecin (HCPT) showed that both types of NPs affected cell viability in a dose-

dependent manner (Fig. 1). Cells exhibited the lowest relative viability when were incubated

with the h-BN-OH-HCPT at 200.0 µgml-1 concentration and at 100.0–200.0 µgml-1

concentrations for h-BN-Au-HCPT. The highest relative viability reduced to 50.0% (results

obtained from CCK-8 assay) was observed for both nanocomposites at 3.125 µgml-1. The

LDH leakage assay demonstrated the highest LDH efflux for h-BN-OH-HCPT at 25.0–200.0

µgml-1 concentrations. Similarly, the effect of the h-BN nanocomposites on human breast

adenocarcinoma cells was determined using the neural red uptake (NRU) assay. The results

showed reduction of MCF-7 viability at 200.0 µgml-1 concentration for h-BN-OH-HCPT and

50.0–200.0 µgml-1concentration for h-BN-Au-HCPT.

Fig. 1. Biocompatibility analysis based on MCF-7cells incubated with h-BN-OH-HCPT and h-BN-Au-HCPT.

Bars represent standard deviation.

The confocal analysis demonstrated internalization process of synthesized nanomaterials.

Moreover, the confocal examination confirmed distribution of NPs inside the cell cytoplasm,

but not in nuclear region of cells.

In summary, it can be concluded that the both tested boron nitride nanocomposites loaded

with 10-hydroxycomptothecin significantly reduce relative cell viability of MCF-7 cells, but

the highest reduction was observed for h-BN-Au-HCPT.

References:

D. Golberg, Y. Bando, Y. Huang, T. Terano, M. Mitome, C. Tang et al., ACS Nano, 4 (2010) 2979.

[2] Q. Weng, X. Wang, X. Wang, Y. Bando and D. Golberg, Chem. Soc. Rev. 45 (2016) 3989.

[3]A.C. Ferrari, F. Bonaccorso, V. Fal’ko, K.S. Novoselov, S. Roche, P. Bøggild, et al., Nanoscale, 7 (2015)

4598.

[4] M. Jedrzejczak-Silicka, M. Trukawka, E. Mijowska, 23rd Polish Conference of Chemical and Process

Engineering, Jachranka-Warszawa, Poland, 2-5 June 2019.

[5] B. Wang, X. Wang, N. Hanagata, X. Li, D. Liu, X. Wang et al., ACS Nano 8 (2014) 6123.

[6] M. Gao, A. Lyalin, T. Taketsugu, J. Phys. Chem. C 116 (2012) 9054.

[7] A.I. Rasel, T. Li, T.D. Nguyen, S. Singh, Y. Zhou, Y. Xiao, et al., J Nanopart Res, 17 (2015) 441.

[8] M. Jedrzejczak-Silicka, M. Trukawka, M. Dudziak, K. Piotrowska, E. Mijowska, Nanomaterials 8(2018) 605.

Acknowledgement: This study was supported by the National Science Centre (Grant no. 2018/02/X/NZ3/00161

and Grant no. 2016/21/N/ST8/02397).

51

The influence of carbon nanotubes on rheological properties of model

pulmonary surfactant

D. Kondej1, T.R. Sosnowski2

1Central Institute for Labour Protection – National Research Institute, Department of Chemical, Aerosol and

Biological Hazards, Czerniakowska 16, 00-701 Warsaw, Poland

e-mail: [email protected] 2Warsaw University of Technology, Faculty of Chemical and Process Engineering, Waryńskiego 1, 00-645

Warsaw, Poland

The aim of this study was to assess the influence of carbon nanotubes (CNT) on

pulmonary surfactant (PS) which is the first barrier that inhaled particles encounter. The term

pulmonary surfactant refers to a complex of surface-active agents existing naturally on the

surface of liquid covering the pulmonary alveoli epithelium. The main role of PS in the lungs

is to maintain an appropriate variation in surface tension during the inhalation - exhalation

cycle. Pulmonary surfactant contributes to the reduction of the surface tension in pulmonary

alveoli, which prevents their collapse in the final stage of exhalation and increases of the

alveoli stability. It also takes part in the self-cleaning of the alveoli from inhaled and

deposited aerosol particles due to liquid flow being the result of Marangoni effects.

The evaluation of changes in rheological properties of model pulmonary surfactant after

contact with carbon nanotubes was conducted with dynamic pendant drop method using

PAT-1M tensiometer (Sinterface Technologies, Germany), i.e. in conditions simulating the

processes occurring in the pulmonary alveoli during the breathing cycle. Pharmaceutical

preparation Survanta (Beractantum; Abbott Laboratories, France) was used as the substance

representing physicochemical properties of natural surfactant. The experiments were carried

out at 36.6 ± 0.2 °C for various CNT concentrations (0.01 - 1 mg/ml) with constant

concentration of PS solution (2.5 mg phospholipids/ml). The droplet was oscillated with

various frequencies (0.1-0.5 Hz) what corresponded to a range of breathing patterns (2 s –

10 s per inhalation – exhalation cycle).

It was found that carbon nanotubes studied influence the changes in rheological

parameters of oscillated air/liquid interface.

Fig. 1. Surface elasticity and viscosity of oscillated air/liquid interface of PS contacted with multiwalled carbon

nanotubes MWL-8 (diameter <8 nm, length 10 – 30 μm, specific surface area 500 m2/g; Cheap Tubes Inc., USA)

In all cases, the surface elasticity increases in a dose-dependent manner when CNT are

present in the system. An increase in the oscillation frequency of the air/liquid interface of PS

results in an increase in surface elasticity and a decrease in surface viscosity of air/liquid

interface contacted with the tested CNT. The change in rheological parameters of the

interface indicates a disturbance of viscoelastic properties of the pulmonary surfactant in the

presence of the carbon nanotubes.

52

References:

[1] D. Kondej, T.R. Sosnowski, Environ. Sci. Pollut. Res. 23 (2016) 4660-4669.

[2] D. Kondej, T.R. Sosnowski, J. Nanomater. Article ID 9457683 (2019) DOI: 10.1155/2019/9457683.

Acknowledgement: This paper has been based on the results of a research task carried out within the scope of

the fourth stage of the National Programme “Improvement of safety and working conditions” partly supported

in 2017–2019 — within the scope of research and development — by the Ministry of Science and Higher

Education/National Centre for Research and Development. The Central Institute for Labour Protection –

National Research Institute is the Programme’s main co-ordinator.

53

Averting 2D Ti3C2 and Ti2C MXenes’ cytotoxicity by controlled adsorption

of collagen

A. Rozmysłowska-Wojciechowska1, S. Poźniak1a, A. Szuplewska2, T. Wojciechowski2, M.

Chudy2, W. Ziemkowska2, A. Olszyna1, L. Chlubny3, A. M. Jastrzębska1

1Warsaw University of Technology, Wołoska 141, 02-507 Warsaw 2 Warsaw University of Technology, Noakowskiego 3, 00-664 Warsaw

3 AGH University of Science and Technology, Mickiewicza, 30-059 Cracow ae-mail: [email protected]

Interactions that occur on material-biological matrix interface are of far importance for

the development of new bioactive systems. Understanding and controlling these mechanisms

may lead to new functionalities of the materials used in e.g. nanomedicine. It is expected that

2D materials (incl. MXenes) can face this challenge among other nanostructures. The

MXenes phases are a member of the intriguing family of 2D materials beyond graphene [1].

They are a good candidates for many applications however, their potential toxicity is now of

crucial importance for their further development [2]. Due to the increasing number of reports

suggesting their toxic behavior [3], there is a high demand for in-depth studies on finding

simple, low-cost and green approaches for controlling their interactions towards living

organisms.

Herein, we present a simple, low-cost and fully green approach for controlling potential

cytotoxicity of the 2D MXenes after delamination. We take advantage of interactions that

occur between the surface of MXene phases and natural biomacromolecule – collagen. We

also demonstrate that the step-by-step adsorption and desorption of collagen from the surface

of 2D MXenes can be easily controlled using in situ zeta potential measurements coupled

with dynamic light scattering (DLS) method. The obtained results proved the electrostatically-

driven unprecedented susceptibility of the MXenes’ surfaces to collagen. Surface-

modification reduced MXenes’ toxicity in vitro i.e. lowered decease of cells’ viability as well

as reduced their oxidative stress. This indicates better biocompatibility of the 2D Ti3C2 and

Ti2C MXenes surface-modified with collagen which is involved in many bio-interactions as

an important building block of the human body. The presented study opens a new horizon for

designing of the defined surface properties of the MXenes and paves the way for their future

successful management for nano-medicinal applications.

References:

[1] Naguib M, Kurtoglu M, Presser V, Lu J, Niu J, Heon M, Hultman L, Gogotsi Y, Barsoum M W, Adv. Mater.

23 (2011) 4248-4253.

[2] Lin H, Chen Y, Adv. Sci. 5 (2018) 1800518

[3] Jastrzębska A M, Szuplewska A, Wojciechowski T, Chudy M, Ziemkowska W, Chlubny L, Rozmysłowska

A, Olszyna A, J. Hazard. Mater. 339 (2017) 1-8.

Acknowledgments: The study was accomplished thanks to the funds allotted by the Ministry of Science and

Higher Education from the budget for science in the years 2016-2019 (project no. JP2015027774) as well as

National Science Centre, within the framework of the research project ‘SONATA BIS 7’ no.

UMO-2017/26/E/ST8/01073.

54

Adhesion of vanadium phthalocyanine to graphene and gold surfaces –

first-principles study

M. Mabrouk, J.A. Majewski

Faculty of Physics, University of Warsaw, L. Pasteura 5, 02-693 Warszawa, Poland


The planar systems, such as graphene, silicene, hexagonal boron nitride, planar transition

metal dichalcogenides exhibit intriguing properties, and at present are considered as the most

promising candidates for future applications in the whole plethora of fields including nano-

electronics, optoelectronics, and spintronics. The functionalization of these layered systems

with molecular nanomagnets (e.g., with so-called single molecular magnets, SMM) can

increase the number of functionalities exhibiting by these systems and lead to tunable array of

magnetic nano-crystals on surface of a system, and then to the novel spin-based technologies.

In this communication, we study the electronic and magnetic properties of Vanadium

phthalocyanine molecule (V-Pc) adsorbed on graphene and Au(111) surface. These studies

are based on theoretical calculations within the density functional theory (DFT) employing

the computer packages VASP [1] and SIESTA [2]. In particular we study adsorption energies

of V-Pc molecules, the induced changes of the geometry of the system with grafted V-Pc

molecule, and magnetic properties of the system, including the interaction between the SMM

and the substrate. In both packages we use the generalized gradient approximation for

exchange-correlation energy functional and van der Waals correction, however, the electron-

ion interaction is accounted for employing projector augmented wave (PAW) and norm-

conserving Troullier-Martins pseudopotentials in the VASP and SIESTA codes, respectively.

Our studies reveal that the adsorption of the V-Pc molecule to both graphene and gold surface

is possible and we determine the energetically most stable geometry of the grafted molecule.

In particular, the most favorite adsorption site of V-Pc molecule to Au (111) surface is the fcc

site as depicted in the Figure below. Our present work sheds light on physical mechanisms of

the SMMs adsorption to half-metallic and metallic surfaces and opens up new prospects for

design of novel spintronic devices.

Figure: V-Pc on Au(111) surface/ Fcc site

References: [1] G. Kresse, J. Furthmuller, Phys. Rev. B 54 (1996) 11169.

[2] J. Soler, E. Artacho, J. D. Gale, A. Garcia, J. Junquera, P. Ordejón, D. Sanchez-Portal, J. Phys. Condens.

Matter 14 (2002) 2745.


2016/23/B/ST3/03567.

55

Theoretical and spectroscopic characterization of porphyrin/graphene

oxide nanohybrid

E. Gacka1, A. Kubas2, M. Mazurkiewicz-Pawlicka3, A. Małolepszy3, L. Stobiński3,

A. Wójcik4, B. Marciniak1, A. Lewandowska-Andrałojć1

1 Faculty of Chemistry, Adam Mickiewicz University, Uniwersytetu Poznańskiego 8, 61-614 Poznan, Poland 2Institute of Physical Chemistry, Polish Academy of Sciences, Kasprzaka 44/52, 01-224 Warsaw, Poland

3Faculty of Chemical and Process Engineering, Warsaw University of Technology, Warynskiego 1,

00-645 Warsaw, Poland 4Helmholtz-Zentrum Dresden-Rossendorf, Institute of Ion Beam Physics and Materials Research, Bautzner

Landstraße 400, 01328 Dresden, Germany


Noncovalent hybrids of graphene oxide and porphyrins are noted for photoinduced

electron transfer. The development of novel graphene-based materials might be very useful

especially in the context of the possible application in solar fuel generation.[1,2,3] Noncovalent

nanocomposite of 5,10,15,20- tetrakis(4-(hydroxyl)-phenyl) porphyrin (TPPH) and graphene

oxide were synthesized at two different pH: 6.8 and 3. Nanohybrids were characterized by

stationary and time-resolved absorption and emission spectra.

Changes in UV-Vis spectra during addition of GO to TPPH solution confirms that

nanohybrid is formed in both neutral and acidic environment but it is more favorable in low

pH. (Fig.1) The fluorescence emission of the TPPH is quenched by the addition of GO and no

new emission band is built. Changes in the absorption spectra and fluorescence quenching

proclaim that interactions between graphene oxide and TPPH molecules occur already in the

ground state. These interactions cause static quenching of TPPH emission as evidenced by the

no shortening of TPPH fluorescence lifetime with the GO addition. Surprisingly, fluorescence

Fig.1. A. Absorption spectra measured during the process of titration of 3 mL of 3.0 μM EtOH−H2O (1:2 v/v)

solution of TPPH (pH 6.8) with 0.4 mg mL−1 of GO dispersion (0−0.025 mg mL−1). B. Absorption spectra of

mixture of TPPH (3 μM) with GO (0.025 mg mL−1) (solid line), and the same mixture after addition of acid to

pH 3 (dotted line).

has not been detected for the TPPH-GO nanohybrid what indicates that very fast deactivation

process takes place. Ultrafast time-resolved transient absorption spectroscopy demonstrated

that the singlet excited-state lifetime of TPPH (pH 3) adsorbed on the GO sheets was

decreased in the presence of GO from 1.4 ns to 12 ps but no electron-transfer products were

detected. It is highly plausible that electron transfer takes place and is followed by fast back

electron transfer [4].

300 400 500 600 700 800

0,0

0,5

1,0

1,5

200l

0l

200l

0l

699

452Ab

s

nm

418

300 400 500 600 700 8000,0

0,2

0,4

0,6

0,8

1,0452

699

Abs

nm

418

A B

56

The experimental results were additionally supported by theoretical calculations that

included optimizations of the ground-state structures of neutral TPPH in pH 6.8 and

protonated TPPH2+ in pH 3 and their complexes with a molecular model of GO.(Fig.2)

Fig.2. Top: Calculated (BP86 + D3gCP/def2-TZVP) structures of TPPH−GO and TPPH2+−GO complexes.

Bottom: ±0.03 a.u. isosurface plots of selected frontier orbitals along with corresponding orbital energies

obtained at the BHLYP/def2-TZVP level.

The interaction of TPPH with GO leads to twisting of the side rings relative to the

porphyrin core from 61° to 40°. On the other hand, the interaction of protonated TPPH2+ with

graphene leads to a negligible decrease of the dihedral angle between the plane of porphyrin

and side ring from 39° to 34°. This is in agreement with the observed small shift of the Soret

band upon the addition of GO in pH 3. The HOMO, for both of the investigated complexes, is

located on the porphyrin entity. Also, the LUMO for TPPH2+−GO is located primarily on the

porphyrin entity, whereas for TPPH−GO, the LUMO orbital is located on GO. Thus, the

decrease of the dihedral angle by 21° along with the charge-transfer character of the

HOMO−LUMO transition for the TPPH−GO complex explains the observed significant

changes in its UV−Vis spectra, that is, the red shift of the Soret band by 34 nm and the build-

up of the new band with a maximum at 699 nm. The values of interaction energies of TPPH

and TPPH2+ with GO energies are −22.4 and −58.0 kcal mol−1 for TPPH−GO and

TPPH2+−GO, respectively. In addition, the center-to-center distance between TPPH2+ and GO

was found to be smaller than TPPH−GO nanohybrid. (Fig.2) Therefore, the effective

interaction and electronic coupling matrix element between GO and porphyrin will be

stronger in the former case.[4]

References:

[1] M. Zhu, Z. Li, B. Xiao, Y. Lu, Y. Du, P. Yang, X. Wang, ACS Appl. Mater. Interfaces, 5 (2013) 1732-1740.

[2] A. Wojcik, P. V. Kamat, ACS Nano, 4(11) (2010) 6697-6706.

[3] Y. Wang, Y. Zhang, J. Chen, Z. Dong, X. Chang, Y. Zhang, Electrochemistry, 83(11) (2015) 950-955.

[4] E. Gacka, A. Wojcik, M. Mazurkiewicz-Pawlicka, A. Malolepszy, L. Stobiński, A. Kubas, G.L. Hug,

B. Marciniak, A. Lewandowska-Andralojc, J. Phys. Chem. C, 2019, 123 (6) 3368–3380.

Acknowledgement: Authors acknowledge the National Science Centre for financial support (project no.

2015/19/D/ST5/00682).

57

Thermal properties of layered materials probed by Raman spectroscopy

A.P. Gertych, K. Czerniak-Łosiewicz, M. Świniarski, M. Zdrojek, J. Judek

Faculty of Physics, Warsaw University of Technology, Koszykowa 75, 00-662, Warsaw, Poland


Raman spectroscopy has proven to be a fast, effective and reliable tool for studying

properties of 2D materials and thin films [1]. Here, we present a study of phonon properties of

exfoliated layered films (for example MoS2, WS2) in order to probe their thermal properties.

We focus on phonon properties as a function of ambient temperature and local optical

heating, which combined with numerical simulation of heat dissipation can lead to the

extraction of total interface conductance and anisotropy of thermal conductivity [2]. All

measurements were taken in an ambient atmosphere and special attention was paid to their

stability and non-destructive character [3].

This work contributes to a better understanding of the thermal properties of thin films,

which are crucial for heat management in thin film applications.

Figure 1. Model of the experiment. (a) Temperature distribution in MoS2/Si system heated by Raman laser beam.

κin – in-plane thermal conductivity of MoS2, κout – out-of-plane thermal conductivity of MoS2, g – thermal

conductance of MoS2/Si interface. (b) Exemplary result of MoS2 thermal conductivity anisotropy. The figure

shows experimental and simulation results of temperature increase in MoS2 on 1mW of absorbed laser power as

a function of distance from focus (spot size variation).

References:

[1] Paillet, M., Parret, R., Sauvajol, J. L., & Colomban, P. Journal of Raman Spectroscopy 49 (2018): 8.

[2] Judek J., Gertych, A. P., Świniarski, M., Łapińska, A., Dużyńska, A., & Zdrojek, M. Scientific reports 5

(2015): 12422.

[3] Judek, J., Gertych, A. P., Krajewski, M., Czerniak, K., Łapińska, A., Sobieski, J., & Zdrojek, M. Carbon, 124

(2017): 1.

Acknowledgments: This work was supported by the Polish Ministry of Science and Higher Education within the

Diamond Grant programme (0217/DIA/2016/45)

(a) (b)

58

New hybrid materials based on carbon nanotubes and metal alloys

D. Kulawik, W. Ciesielski, A. Ciesielska, K. Kozieł, V. Pavliuk

Institute of Chemistry, Jan Dlugosz University in Czestochowa,

13/15 Armii Krajowej Ave., 42-200 Czestochowa, Poland

Storage the hydrogen in the solid materials is safe and effective way to store energy. This

type of cell can be used both for stationary and mobile equipment. The main requirements for

modern materials for hydrogen storage in the automotive industry are: high gravimetric

density, easy absorption / desorption of hydrogen at normal temperatures and pressures, low

price of materials and their ecological safety. Conventional hydrides, such as LaNi5H6 and

derivatives of zirconium and titanium alloys are commonly used in hydrogen storage systems

have the storage capacity of less than 2% by weight of hydrogen. Four major groups of

suitable materials include: a) carbon and other materials with high surface areas (nanotubes,

graphite nanofibers, zeolites, etc.); b) H2O-reactive chemical hydrides (NaH, LiH); c)

hydrides complex (LiAlH4, NaAlH4, etc.), borohydrides amine (NH3BH3); d) alloys and

intermetallics. Hydrides of rare earth metal (R) and transition metal alloys (T) are very well

researched. These materials show good kinetics, but capacity and desorption temperature are

low. On the other hand the hydrides complex of the lithium alloys have enjoyed in recent

years, large attention as materials for energy storage in the future. The hydrogen content is

achieved in accordance with the literature value of 18% mass for LiBH4. However, these

compounds only desorb hydrogen at a temperature about 600°C. Large prospects in the

process of sorption / desorption of hydrogen and therefore solving of this problem are

lightweight multicomponent lithium alloys and carbon nanotubes. The addition of mono- and

multi-walled carbon nanotubes to as described above alloys increase the absorption of

hydrogen.

Acknowledgement: This project was financially supported by the National Science Center fund awarded based

on the decision 2015/19/N/ST8/03922.

59

Studies of graphene/1T-TaS2 and 1T-TaS2/graphene heterostructures by

STM/STS/LEED/ARPES/DFT technics

I. Lutsyk1, P. Dabrowski1, M. Rogala1, E. Lacinska2, N. Olszowska3, M. Kopciuszynski4,

L. Zurawek4, K. Szalowski1, M. Gmitra5, J. J. Kolodziej3, A. Wysmolek2, Z. Klusek1

1Department of Solid State Physics, University of Lodz, Pomorska 149/153, 90-236 Lodz, Poland

e-mail: [email protected] 2Institute of Experimental Physics, Faculty of Physics, University of Warsaw,

Pasteura 5, 02-093 Warsaw, Poland 3 Faculty of Physics, Astronomy, and Applied Computer Science, Jagiellonian University,

Lojasiewicza 11, 30-348 Krakow, Poland 4Institute of Physics, Maria Curie-Sklodowska University,

Pl. M. Curie Sklodowskiej 1, 20 031 Lublin, Poland 5Department of Theoretical Physics and Astrophysics, Institute of Physics, P. J. Šafárik University,

Park Angelinum 9, 040 01 Košice, Slovakia

Transition metal dichalcogenides (TMDCs) belong to the class of materials, which have

the general formula MX2, where M is a transition metal atom of the group IV (Ti, Zr, Hf),

V (V, Nb, Ta) or VI (Cr, Mo, W), while X is a chalcogen atom (S, Se, Te). TMDCs

are materials with high spin-orbit coupling (SOC) and semiconductor or metallic properties

at room temperature. At present, they are mainly considered as part of heterostructures with

graphene, in which TMDCs induce magnetic properties. For our heterostructure, we selected

tantalum disulfide, which exhibits a tetragonal symmetry with octahedral coordination

of the Ta atom (1T-TaS2). Among all the TMDCs, 1T-TaS2 shows the richest phase diagram,

including a pronounced metal-insulator transition (MIT) and a sequence of different charge

density wave (CDW) transformations. An undistorted normal phase of 1T-TaS2 exists

in the temperature range of 570–550 K. Upon lowering the temperature an incommensurate

CDW (ICCDW) ordering is observed below 550 K and then a nearly commensurate phase

(NCCDW) at about 350 K. Finally, a commensurate CDW (CCDW) phase is reached

at 180 K. When temperature is increasing transformation from CCDW to NCCDW appears

at the temperature higher than 180 K, i.e. a hysteretic behavior is observed.

The aim of the undertaken research is to combine 1T-TaS2 with graphene into

a heterostructure, which will allow to employ the unique properties of both components

of the heterostructure. Such a hybrid has the chance to simultaneously provide the ability

to effectively generate (1T-TaS2) and transport (graphene) spin-resolved charge carriers.

For this purpose, 1T-TaS2 will be exfoliated under ultra-high vacuum conditions, which will

prevent its oxidation. In the next step, graphene/1T-TaS2 systems will be fabricated with

graphene transferred by wet method on 1T-TaS2 crystal. Similarly, reversed heterostructures

will be created with thin flakes of 1T-TaS2 deposited on graphene (1T-TaS2/graphene).

We will present our recent LEED/STM/STS/ARPES experiments on 1T-TaS2 carried out

at different temperatures accompanied with DFT calculations showing successive

transformation of CDW and evolution of the electronic structure expected from the theoretical

calculations. We will also show the evolution of the electronic structure of graphene/1T-TaS2

heterostructure. We experimentally prove that graphene is p-type doped due to the proximity

effect as predicted from our DFT calculations. Besides, we will present results

of 1T-TaS2/graphene system by STM/AFM and Kelvin probe force microscopy (KPFM).

Acknowledgements: The work was financially supported by The National Science Centre (Poland) under grant

2015/19/B/ST3

60

Photoconductivity of boron nitride layers grown by MOVPE

J. Rogoża1, J. Binder1, K. Pakuła1, J. Judek2, M. Zdrojek2, R. Stępniewski1, A. Wysmołek1

1Faculty of Physics, University of Warsaw, Pasteura 5, 02 – 093 Warsaw, Poland

2 Faculty of Physics, Warsaw University of Technology, Koszykowa 75, 00-662 Warsaw, Poland


Boron nitride (BN) is a very promising candidate for optoelectronic applications in the

deep ultraviolet spectral range due to its exceptional physical properties such as high chemical

stability, thermal conductivity and wide bandgap energy. A large cross section for neutron

capture renders BN an outstanding candidate for neutron detectors, while the possibility of

effective p-type doping opens up new possibilities of application as a transparent contact in

UV emitting devices based on nitrides. The development of various applications based on BN,

including hybrid structures composed of different 2D materials, requires large surfaces of

high quality material with desired optical and electrical properties and is strongly correlated

with the knowledge of the basic properties of this material.

In this communication initial studies of photoconductivity of epitaxial BN layers grown

by Metal Organic Vapour Epitaxy (MOVPE) are presented. The investigated sample was

doped with magnesium. In order to activate the dopants and increase the conductivity the

sample was additionally annealed in nitrogen atmosphere. Gold contacts with comb-shaped

structures were prepared using electron beam lithography in a lift-off process (Fig. 1).

Figure 1. Optical images of the investigated sample showing (a) all structures and (b) a zoom-in of a single

comb-shaped contact structure.

In order to study the photocurrent, light from a mercury lamp was used. Our initial studies

show that magnesium doping substantially increases electrical conductivity of the epitaxial

BN layers grown by MOVPE. Illumination of the sample leads to the generation of an

additional current which could be associated with the photoionization of the defect and

impurity states in the epitaxial BN material.

The obtained results confirm that magnesium doping indeed significantly reduces the

resistivity and that illumination, even with a light source of maximum intensity well below the

bandgap, leads to observable changes of the electric properties. These findings constitute the

first important step towards spectrally resolved experiments allowing to study the

photoionization of defect and impurity states, as well as excitonic resonances by employing a

light source with a significant light output above 6 eV.

61

Theoretical studies of the optical properties of MnPS3 – a 2D magnetic

material

M. Birowska1, J. Kunstmann2

1University of Warsaw, Faculty of Physics, Pasteura 5, 02-093 Warsaw, Poland 2Department of Chemistry and Food Chemistry TU Dresden, 01062 Dresden, German

Atomically thin, magnetic materials have recently gained a lot of attention in the field of

two-dimensional (2D) materials [1]. Single magnetic layers with critical temperature above

room-temperature are extremely attractive for fundamental studies and could potentially be

the basis for a new class of information storage.

Probing the magnetic order of the 2D systems by conventional experimental means is

very challenging. However, it is well known, that even in the single layer limit,

semiconducting two-dimensional materials strongly absorb light. Therefore, optical

spectroscopy is a good method for their characterization.

In order to shed light on the intriguing phenomena of 2D magnetism, we present

theoretical investigations of the optical properties of the layered material MnPS3, which is

one important example from the large family of transition metal phosphorus trisulfide

(MPS3)[2].

Our study reveals, that the interband absorption spectrum, which is proportional to the

imaginary part of the dielectric function, is very similar for different possible magnetic order

of MnPS3. On the other hand, the calculated effective masses of electrons and holes exhibit

an anisotropic behaviour and they do depend on the magnetic order. Aforementioned

properties are reflected in the binding energy of excitons in the studied systems. In addition,

our studies reveal that the Hubbard correction (U) in the DFT+U approach can have a crucial

impact on the prediction of the optical and electronic properties of the investigated structures.

References:

[1] M. Gibertini et al., Nat.Nanot. vol. 14, p. 408 (2019).

[2] M. Evain et al., J. of Solid State Chem. vol. 7, p. 244 (1987).

Acknowledgments: MB is funded by the NCN grant no. UMO-2016/23/D/ST3/03446. We thank Gotthard Seifert

(TU Dresden, Germany), Kai Trepte (TU Dresden, Germany) and Zakhar Popov (MISIS, Russia) for helpful

discussions.

62

Extraordinary transport properties of disordered graphene structures of

annealed charcoal

M. Dudyński1, K. Jurkiewicz2, A. Jamróz3, J. A. Majewski3

1Model Technologies and Filtration Ltd., Przybyszewskiego 73/77, 01-824 Warszawa, Poland 2Institute of Physics, University of Silesia, ul. 75 Pułku Piechoty 1, 41-500 Chorzów, Poland

3Faculty of Physics, University of Warsaw, L. Pasteura 5, 02-693 Warszawa, Poland


In recent years, the extensive studies of graphene-like materials revealed their enormous

potential for applications ranging from electronics and optoelectronics through medical

sciences to high-strength mechanics. However, one of the biggest obstacles of the in the fast

development of the technologies based on graphenic systems is the lack of scalable, low-cost

and efficient methods of graphene synthesis. Also ecological aspects of future innovative

technologies are getting more attention nowadays, therefore, ‘green’ substrates, such as

lignin-based biomass [1], has been also investigated. The wood constitutes a cheap and

abundant biomass source of carbon allowing for growth of graphenic materials.

In this communication, we report remarkable changes in electronic and magnetic

properties of charcoal resulting from high temperature sintering of carbon material. We

observe change in resistivity from chopping type typical for samples heated below 1000 C,

into conducting band like behavior for high temperature treatments. These highly conductive

samples exhibit also strong Hall effects and a wealth of magnetic properties including weak

localization behavior at low temperatures. These properties are usually connected with well-

ordered structures and are in apparent contradiction with our understanding of actual structure

of biomass carbon, being usually described as disordered. To gain understanding of the

physical mechanisms that determine our intriguing findings, we have performed extensive

experimental studies of the morphology and the atomic structure of the samples augmented by

computer simulations. Further, employing empirical tight-binding method, we calculate the

electronic structure of the studied systems and their transport electric properties within the

real space order O(N) transport formalism [2].

References: [1] Q. Du, et al., Diamond & Related Materials, 109 (2018).

[2] Dinh van Tuan, Charge and Spin Transport in Disordered Graphene-based Materials,

pp. 35-54, Springer (2016).

Acknowledgements: A.J. and J.A.M. acknowledge support of National Science Centre in Poland (UMO-

2017/25/N/ST3/00660 and UMO 2016/23/B/ST3/03567.

63

Recycling the substartes and the product of the carbonized metal-organic

frameworks as a key process prior industrial applications

K. Cendrowski, M. Trukawka, W. Kukułka, E. Mijowska

Katedra Fizykochemii Nanomateriałów, Wydział Technologii i Inżynierii Chemicznej, Zachodniopomorski

Uniwersytet Technologiczny w Szczecinie, ul. Al. Piastów 45, 70-311 Szczecin


In this contribution, we present the potential industrial application of carbonized metal–

organic frameworks (MOF) structures, used as gas and pollutant adsorbent and electrode

material for supercapacitors. The structural properties of the carbon structures is formed as the

effect of carbonization of metal-organic framework. Depending on the MOF structure and

chemical carbonized MOFs will different in terms of chemical composition, unique

morphology and physical properties.

The carbonization of metal–organic frameworks based on cobalt and terephthalic acid

(CoOF) allows the formation of a hybrid of multi-layered carbon structures with metal and

metal oxide nanoparticles placed between them [1]. The cobalt are placed between the carbon

layers what limits the dissolution of cobalt nanoparticles and protects the environment from

its toxicity [1,2]. Second studied structure was MOF-5, that carbonized form shows highly

pours structure with high surface area [3]. Due to this, carbonized MOF-5 shows potential for

supercapacitors fabrication [4,5] and gas adsorbent [6]. The possibility of industrial

application of both structure is limited due to the highly toxic, corrosion substrates and waste

used in their synthesis. DMF used for the synthesis of both structures is regarded as toxic for

natural environment and can cause health hazard. Therefore recycling DMF is crucial key

process that prior MOFs industrial applications [2,4].

The possibility of using recycled substrates in synthesis process was also investigated.

Terephthalic acid was obtained from PET bottles, while the organic solvent was distilled and

re-used. The obtained MOFs from recycled substrates, revealed the same morphology as

pristine material [2,4]. Therefore, it is believed that this work highlights the practical

application of carbonized MOFs proving that structure synthesized from waste or recycled

materials shows similar potential as they pristine structures

References:

[1] K. Cendrowski, A. Zenderowska, A. Biegańska, E. Mijowska, Dalton Transactions RCS. 46 (2017) 7722-

7732

[2] M. Barylak, K. Cendrowski, E. Mijowska, Industrial & Engineering Chemistry Research, 571 (2018) 44867-

4879

[3] K. Cendrowski, P. Skumial, P. Spera, E. Mijowska, Materials and Design (2016) 110, 740–748

[4] K. Cendrowski, W. Kukułka, T. Kedzierski. S. Zhang, E. Mijowska, Nanomaterials (2018) 8, 890

[5] W. Kukułka, K. Cendrowski, E. Mijowska, Electrochimica Acta 307 (2019) 582 - 594

[6] W. Kukulka, K. Cendrowski, B. Michalkiewicz, E. Mijowska, RSC Advances 9,32 (2018) 18527-18537

Acknowledgements: The authors are grateful for the financial support of National Science Centre, Poland,

within SONATA 2016/23/D/ST5/01683

64

SWCNTs and MWCNTs as co-catalysts of g-C3N4 for photocatalytic H2

evolution - comparative study

K. Sielicki, M. Aleksandrzak, E. Mijowska

Department of Physicochemistry of Nanomaterials, Faculty of Chemical Technology and Engineering,

West Pomeranian University of Technology, Szczecin, Piastow Ave. 42,

71-065 Szczecin, Poland

Recently, we can observe the increasing interest in clean and renewable sources of

energy. Hydrogen is one of those alternative’s sources, which production and storage is

intensely investigated. One of the advantages of using hydrogen in the process of energy

production is that steam is the only by-product.

Graphitic carbon nitride (g-C3N4) is well known metal-free photocatalyst, which can

absorb the radiation in UV and visible range. Despite its easy one-step synthesis from cheap

organic precursors, like urea or cyanamide, g-C3N4has few shortcomings such as: low

quantum efficiency and fast recombination of photoinduced charge carriers. One of the

popular ways to reduce these disadvantages is the creation of heterojunction with carbon

materials, e.g. carbon nanotubes (CNTs), which show excellent electric and mechanic

properties. CNTs are popular material in many applications, including photocatalysis. Single-

walled carbon nanotubes (SWCNTs) and multiwalled carbon nanotubes (MWCNTs) are

widely investigated, but in photocatalytic processes MWCNTs are mostly used. Here, both

MWCNTs and SWCNTs are used as a co-catalyst for g-C3N4. The obtained materials were

investigated via microscopic techniques: TEM, SEM, spectroscopy techniques: Raman, FTIR,

PL, UV-Vis/DRS and other techniques: EIS and photoinduced LSV. Finally, the photoactivity

of g-C3N4/CNTs composites are studied in the reaction of photocatalytic hydrogen generation

under solar light irradiation.

65

Flammability and thermal conductivity of tungsten disulfide/carbon

nanotube nanocomposites

K. Maślana, E. Mijowska

West Pomeranian University of Technology in Szczecin, Faculty of Chemical Technology and Engineering,

Piastow Ave. 42, 71-065 Szczecin, Poland


Fire is a continuous threat to life and property. It is well known that polymeric materials

are flammable and easy to ignite. Moreover, during combustion they emit a large amount of

smoke, which may be harmful to human life and environment. Therefore, it is very important

to improve thermal properties of these materials. Halogen based compounds are widely used

as efficient flame retardants for polymeric materials. However, these compounds emit

hazardous gaseous for environmental and human life. [1] Metal hydroxides, such as

magnesium or aluminum hydroxides, are also commercially used as flame retardants. To get

satisfactory results it is necessary to use large quantities of those compounds, which

significantly reduce mechanical properties of polymeric composites. [2] Recently, different

nanomaterials such as montmorillonite, carbon nanotubes, graphene and other layered

materials, are intensively investigated to improve thermal properties of polymeric materials.

Here, polymer nanocomposites with good flame retardant properties require use of less

amount of nanofillers, what is desirable for mechanical properties and cost of materials. [3]

In this work the influence of carbon nanotubes and tungsten disulfide nanosheet on flame

retardant properties of polyethylene was investigated. Additional, thermal conductivity of the

produced nanocomposites was compared. The obtained materials were characterized by

Scanning Electron Microscope and thermogravimetric analysis. Thermal properties of

nanocomposites were evaluated using microcalorimeter and Xenon Flash Analysis (XFA).

According to the obtain results it can be concluded that addition of nanofillers have a good

influence on flame retardant properties of polyethylene in comparison to neat polymer.

References:

[1] Y. Hu, X. Qian, L. Song et. al., Fire Safety Science, 2014, 66-82.

[2] S.C. Brown, Plastics Additives. Polymer Science and Technology Series, vol 1, 1998.

[3] C. Wilkie, M.R. Schulz, J. Breu, 20th Annual Conference on Recent Advances in Flame Retardancy of

Polymeric Materials, 2009, 155-159.

Acknowledgements: The authors are grateful for the financial support of National Science Centre OPUS 10

UMO-2015/19/B/ST8/00648.

66

MOF-5 derived carbon as material for CO2 adsorption

W. Kukułkaa, K. Cendrowskia, B. Michalkiewiczb, E. Mijowskaa

a Nanomaterials Physicochemistry Department, West Pomeranian University of Technology, Szczecin, Piastów

Av. 45, Szczecin 70-311, Poland

b Institute of Chemical and Environment Engineering, West Pomeranian University of Technology, Szczecin,

Pulaskiego St. 10, Szczecin 70-322, Poland

The 21st century poses huge challenges for all scientists, especially those regarding

energy storage and environmental protection. Many different questions can be answered by

studies on the adsorption of various gases. The most commonly studied gases for potential

applications are hydrogen (H2), carbon dioxide (CO2) and methane (CH4). One of the most

serious threats about the natural environment is global warming resulting from the greenhouse

effect caused by excessive CO2 emission from different sources like steel or automobile

industries. Carbon dioxide traps radiation, creating ground-level ozone which leads to

disturbances in the daily amplitude of the air temperature. It warms up oceanic waters,

thereby reducing their ability to adsorb CO2 from the atmosphere, creating a vicious circle.

Increased temperature also causes melting of glaciers and continuous increase of the water

level. It certainly has an impact on climate change. Carbon dioxide emission certainly also has

an impact on human health and well-being. Thus, it is necessary to limit its emission by using

specialized filters and adsorbers. Therefore, we need more and more novel materials with high

gas adsorption capacity for all abovementioned gases and we wish that this adsorption takes

place effectively at room temperature.

Therefore, in this study we prepared MOF-5 derived carbon to reveal the efficiency and

thermodynamics of CO2 adsorption process in great details. Porous carbon material was

prepared from metal-organic framework (MOF-5) via carbonization at 1000 ˚C. The obtained

structure consists only of carbon and exhibit BET specific surface area, total pore volume and

micropore volume of 1884 m2/g, 1.84 cm3/g and 0.59 cm3/g, respectively. The structural

analysis allowed to assume that this material is ideal candidate for efficient CO2 adsorption.

The CO2 uptake was 2.43 mmol/g at 25 °C and 1 bar. Additionally, the adsorption in a wide

range of temperatures (25, 40, 60, 80 and 100 °C) and pressures (in range of 0-40 bar) was

investigated.

Fig. 1. SEM images of the carbonized MOF-5 (A,B) and CO2 adsorption isotherms (C).

Acknowledgements: The authors are grateful for the financial support of National Science Centre, Poland,

within SONATA BIS 2012/07/E/ST8/01702.

67

CaCO3 template assistant to synthesize 2D porous carbon flakes from

intumescent flame retardants for high-performance supercapacitors

T. Wang, H. Chen, X. Wen, E. Mijowska


Pomeranian University of Technology, Szczecin, Piastów Ave. 42, 71-065 Szczecin, Poland

In this work, intumescent flame retardants (IFRs) system as carbon precursor reacted with

nano-CaCO3 via crosslinking and subsequent carbonization1, 2, resulting in 2D porous carbon

flakes (PCFs) which possess rich phosphorus and nitrogen dual-doped contents. Using

different mass of nano-CaCO3 as template3-5 to study the different effects of template

nanocasting and self-activation. Remarkably, the obtained PCFs-0.5 electrode displays many

advantages, including abundant pore structures with a total pore volume of 1.07 cm3 g-1, i.e.,

micropores, mesopores and macropores, high specific capacitance of 282 and 307 F g-1 at a

current density of 1 A g-1 and the scan rate of 1 mV s-1 in 6 M KOH electrolyte and excellent

cycling stability (about 94.8% of capacitance retention after 10000 cycles at 10 A g-1 ).This

study provides a facile approach for enhancing the performance of the electrodes by doping

N, P elements and opens new IFRs system applications as supercapacitors in energy storage

fields.

Fig.1. Illustration of intumescent flame retardants (IFRs) as carbon precursors to synthesize N/P dual-doped

porous carbon flakes for supercapacitor.

References

1. Ding, W.; Li, J.; Tao, K., RSC Advances 2014, 4 (64), 34161-34167.

2. Yan, H.; Zhang, J.; Zhang, M.; Du, X.; Ma, S.; Xu, B., Advances in Polymer Technology 2016, 35 (2),

208-214.

3. Wang, Z.; Xiong, Y.; Guan, S., Electrochimica Acta 2016, 188, 757-766.

4. Gao, A.; Guo, N.; Yan, M.; Li, M.; Wang, F.; Yang, R., Microporous and Mesoporous Materials 2018,

260, 172-179.

5. Luo, E.; Xiao, M.; Ge, J.; Liu, C.; Xing, W., Journal of Materials Chemistry A 2017, 5 (41), 21709-21714.

68

Controlled synthesis of Ni-Al layered double hydroxide on exfoliated

molybdenum disulfide nanosheets and its application for flame retarded

polystyrene composites

H. Chen, T. Wang, X. Wen, E. Mijowska



In present paper, NiAl-LDH/MoS2 hybrids were facilely prepared by self-assembly of

exfoliated MoS2 nanosheets and LDH via electrostatic force. The structure and morphology of

the NiAl-LDH/MoS2 hybrids were characterized and then introduced into polystyrene for

reducing its fire hazards1, 2. Compared with single MoS2, NiAl-LDH/MoS2 hybrids showed a

more homogeneous dispersion in the polystyrene matrix and no obvious agglomerates were

observed. Compared with MoS2, the addition of LDH/MoS2 hybrids endowed more excellent

fire resistance to polystyrene matrix, which was reflected by the significantly reduced peak

heat release rate, total heat release and total smoke production. At the same time, transition

metal element nickel can greatly catalyze carbonization of polymer combustion products3, it is

beneficial to the improvement of flame retardant properties of composite materials. In

addition, A rational flame retardant mode of action for NiAl-LDH/MoS2 hybrids was

proposed based on the analysis of char residues.

Fig. 1 PS and its composites by cone calorimeter testing at an external radiant flux of 50 kW/m2 :(a) Heat release

rate curves (HRR); (b) Mass loss curves (MLR); (c) Total Smoke Production curves (TSP); (d) CO Production

curves (COP).

References:

1. Zhou, K.; Zhang, Q.; Liu, J.; Wang, B.; Jiang, S.; Shi, Y.; Hu, Y.; Gui, Z., RSC Advances 2014, 4 (26),

13205-13214.

2. Zhu, Y.; Shi, Y.; Huang, Z.-Q.; Duan, L.; Tai, Q.; Hu, Y., Composites Part A: Applied Science and

Manufacturing 2017, 99, 149-156.

3. Shen, Y.; Gong, W.; Zheng, B.; Meng, X.; Gao, L., Polymer Degradation and Stability 2016, 129, 114-124.

69

Highly Efficient Conversion of Plastic Waste into Carbon Nanosheets and

Enlarged its Interlayer Spacing for High Electrochemical Performance

X. Liu, X. Chen, E. Mijowska



Two-dimensional carbon nanosheets (CNS) have received extensive attention because of

their robust architecture and superior thermal/electrical properties,1-3 whereas their wide

application is still highly restricted by many obstacles. Herein, waste polypropylene (PP) is

efficiently carbonized into CNS with a high yield of 65.8 % by a combined catalyst precursor

of ferrocene and sulphur. It is proved that the as-formed Fe7S8 nanosheets promote the

carbonization of PP as well as serve as template for the formation of CNS. After KOH

activation, the obtained porous carbon nanosheets (PCNS) show an increased interlayer

spacing from 0.38 nm to 0.62 nm, which is believed to benefit the electrolyte ions storage

compared to the original CNS. The specific capacitance of 282 F g-1 is obtained for PCNS in

6M KOH electrolyte, much higher than that of CNS (66 F g-1). The molecule dynamic (MD)

simulation was further conducted to confirm the key role of increased interlayer spacing in

enhanced ion storage capacity, which is well consistent with the experiment result. These

findings will open a new avenue for recycling plastic waste into two-dimensional carbon

materials and in-depth understanding the relationship between interlayer spacing and the

electrochemical performance.

Figure 1. Schematic drawing for the formation process of CNS from waste PP.

References:

1. Yang, J. Q.; Zhou, X. L.; Wu, D. H.; Zhao, X. D.; Zhou, Z., S-Doped Advanced Materials 2017, 29 (6).

2. Pan, J.; Chen, S. L.; Zhang, D. P.; Xu, X. N.; Sun, Y. W.; Tian, F.; Gao, P.; Yang, J., Advanced Functional

Materials 2018, 28 (43).

3. Karan, S.; Samitsu, S.; Peng, X. S.; Kurashima, K.; Ichinose, I., Science 2012, 335 (6067), 444-447.

70

WS2 and MoS2 rods as high efficient electrocatalyst in oxygen evolution

reaction

K. Wenelska, K. Maślana, M. Biegun, E. Mijowska

Nanomaterials Physicochemistry Department, West Pomeranian University of Technology, Szczecin, Piastow

Ave. 42, Poland, email:[email protected]

Shrinking fossil fuel resources, climate change and environmental situations due to

carbon release have made finding alternative sources of clean energy very important aspect of

researches. For many years scientists are looking for new, environment friendly and low-cost

way to produce electrical power, such as fuel cells , water splitting , metal-air batteries and

CO2 to fuel conversion . The simplest, most efficient, and reliable in energy conversion are

renewable sources [1,2].

Oxygen evolution reaction (OER) via electrocatalytic water splitting is crucial for

efficient electrochemical energy storage and conversion. Herein, we describe the preparation

of rod-like structure of tungsten disulphide (WS2) and molybdenum disulphide (MoS2) as

efficient catalysts for OER. Exfoliated tungsten disulphide and molybdenum disulphide were

used as a source of the rods. The reshaping process required high temperature treatment with

the assistance of hydrogen and ethylene. We propose new structure with promising variety of

applications. The rod-like structures were manifested by high-resolution transmission electron

microscopy measurements including HAADF intensity line profile. Further structural insights

were obtained in X-ray diffraction and Raman spectroscopy. The structures exhibited

apparent electrocatalytic activity toward OER overpotential = 351 mV and overpotential =

365 mV at 10 mA/cm2 for WS2-rodes and MoS2- rods, respectively.

Fig1. (A) SEM, (B) TEM images of WS2- rods and (C) SEM, (TEM) images of MoS2- rods.

Literature:

[1] B.C.H. Steele, A. Heinzel, Nature, 414, 345-352 (2001).

[2] M.G. Walter, E. L. Warren, J.R. McKone et al., Chem. Rev., 110, 6446-6473 (2010).

Acknowledgements: This work was financially supported by National Science Center Poland (UMO-

2015/19/B/ST8/00648).

71

Electrochemical Nitrogen Reduction Reaction conducted on MoS2-Fe_rods

heterocatalyst

M. Biegun, K. Maślana, K. Wenelska, X. Chen, E. Mijowska

Katedra Fizykochemii Nanomateriałów,

Zachodniopomorski Uniwersytet Technologiczny w Szczecinie, ul. Al. Piastów 17, 70-315 Szczecin


Ammonia is one of the most produced chemicals in the world.[1] Approximately 88% of

the ammonia global production is used as fertilizers both as its salts or anhydrous. It helps

growth a yield when introduced to the soil, of the crops like maize and wheat.[2]

At present, overwhelming ammonia production in global scale is conducted by a classic

Haber-Bosch process. It’s a high temperature (300-500ºC), high pressure (15-30 Mpa)

heterogeneous catalytic (iron or ruthenium-based) process which consumes about 2% of the

world energy and 5% of the natural gas production. Moreover, it generates annually 300 Mt of

the CO2 emission.[3] Due to the high environmental impact, it is highly welcome to develop a

more eco-friendly process to obtain ammonia. Electrochemical Nitrogen Reduction Reaction

(NRR) can become a clean, carbon-free and efficient NH3 source produced from N2 and H2O

by using heterogeneous catalyst under ambient conditions and energy produced from

renewable sources.[4] However, there are still challenges to confront. One of them is to

develop a highly selective and robust electrocatalyst. Hitherto three kinds of catalysts were

developed: noble metal-based, non-noble metal-based and metal-free electrocatalyst.

Generally, the structure morphology has a very high effect on the activity of the

heterocatalyst.

This presentation of the research in a paper poster form describes the preliminary NRR

test of the MoS2-Fe rods like structure catalyst. Experiments utilised the two-compartment

cell with ion-conductive Nafion 117 membrane, 0.5M K2SO4/0.02M H2SO4 electrolyte,

99.999% nitrogen purity and catalyst covered the graphite foil as the working electrode. The

indol-phenol colourimetric method was used to determine the ammonia content during

electrocatalysis process. Figure 1 present SEM image of the graphite working electrode

surface covered by MoS2-Fe rods like a catalyst and Nafion binder.

Figure 1. SEM image of the graphite working electode surface covered by MoS2-Fe-rods like

catalyst and Nafion binder. References:

[1] U.S. Geological Survey, Mineral commodity summaries 2019, U.S. Geological Survey (2019)

[2] Lassaletta, L., Billen, G., Grizzetti, B., Anglade, J. and Garnier, J. Environmental Research Letters 9,

105011 (2014).

[3] S. Mukherjeea, D. A. Cullenb, S. Karakalosc, K. Liud, H. Zhang, S. Zhao, H. Xu, K. L. More, G. Wang and

G. Wu, Nano Energy, 48, 217–226. (2018)

[4] A. Banerjee, B. D. Yuhas, E. A. Margulies, Y. Zhang, Y. Shim, M. R. Wasielewski and M. G. Kanatzidis, J.

Am. Chem. Soc., 137, 2030–2034. (2015)

72

The modification of carbon materials for methane storage

K. Kiełbasa, J. Sreńscek-Nazzal




The methane adsorption on the activated carbon is the subject of great interest thanks to

its practical utilization. Among commonly used fossil fuels, currently methane seems to be the

one that will be used more and more in the near future because of its relative abundance,

‘cleanliness’ and surely the greatest ‘ecologicalness’. Methane may be used to supply engines

in vehicles and it could be great in replacing common liquid fuels. The growing ecological

problems are mainly caused by the air pollution by motor vehicles moreover the natural fossil

reserves that are of ‘geological’ origin are estimated to be insufficient. In view of the above-

mentioned problems numerous studies have been dedicated to the utilization of alternative

and renewable energy sources. Methane is currently considered as very promising fuel and it

can be the energy source of the future.

The critical issue for the methane adsorption is the careful selection of the

adsorbent/storage material. A promising adsorbent material should have well developed

suitable porosity and high natural gas storage capacity. An optimal adsorbent should also have

large surface area, readily controlled structure, good hydrophobicity and high working

capacity at a reasonable cost [1-2]. The methane adsorption can be enhanced by varying the

chemical or textural properties of adsorbent/storage materials using appropriate techniques

[3-4]. The adsorption characteristic is the most relevant parameter.

In this work, we present the modification of commercial activated carbon named CWZ-22

(GRYFSKAND, Ltd., Poland). The activated carbon was modified by a saturated solution of

KOH and K2CO3 for 3h. The mass ratio of the modifying agent to carbon (M:C) was varied in

the range from 1 to 4. A modification process was carried out in the temperature range of

600-850 oC. The process was conducted in the nitrogen atmosphere (flow of 18 dm3/h). The

prepared activated carbon containing the decomposition products of potassium hydroxide or

potassium carbonate were washed with distilled water to achieve a neutral reaction.

Subsequently, the activated carbon was dried at temperature of 110 oC for 16h.

The influence of the modification conditions on the specific surface area, the pore volume

as well as the micropore volume were compiled in Table 1. The modified CWZ-22 carbons

exhibited well developed specific surface area (SBET). The highest value of SBET amounted to

1827 m2/g was determined in the CWZ-22 carbon which was modified by KOH at

temperature 850 oC.

Table 1. Textural properties of the activated CWZ-22 carbons modified by KOH and K2CO3 determined on the

basis of the low-temperature adsorption isotherms of N2 (-196 oC)

Carbon SBET

[m2/g]

Vpor

[cm3/g]

Vmic

[cm3/g]

Carbon SBET

[m2/g]

Vpor

[cm3/g]

Vmic

[cm3/g]

CWZ-22 908 0.47 0.29

CWZ-22:KOH_600=1 938 0.50 0.29 CWZ-22:K2CO3_600=1 958 0.54 0.29

CWZ-22:KOH_650=1 991 0.54 0.29 CWZ-22:K2CO3_650=1 981 0.55 0.29

CWZ-22:KOH_700=1 1066 0.59 0.31 CWZ-22:K2CO3_700=1 1010 0.56 0.30

CWZ-22:KOH_750=1 1103 0.59 0.33 CWZ-22:K2CO3_750=1 1062 0.57 0.32

CWZ-22:KOH_800=1 1286 0.70 0.34 CWZ-22:K2CO3_800=1 1097 0.57 0.34

CWZ-22:KOH_850=1 1322 0.71 0.37 CWZ-22:K2CO3_850=1 1212 0.62 0.37

CWZ-22:KOH_850=2 1349 0.75 0.37 CWZ-22:K2CO3_850=2 1219 0.62 0.38

73

CWZ-22:KOH_850=3 1355 0.81 0.37 CWZ-22:K2CO3_850=3 1224 0.63 0.38

CWZ-22:KOH_850=4 1827 1.02 0.37 CWZ-22:K2CO3_850=4 1271 0.66 0.38

The carbons with regard to the greatest specific surface were selected for the

investigations of methane adsorption under high pressure conditions. The investigations of

methane adsorption up to a pressure of 45 bar over different temperatures with selected

activated CWZ-22 carbons were shown in Figure 1. In the Figure, the points symbolize

experimental data, whereas the lines are a result of mathematical modeling. It was concluded

that the Sips model indicated the best fitting to the experimental results.

0 5 10 15 20 25 30 35 40 450

2

4

6

8

Pressure [bar]

25 40

60 80

100 120

140 160

SIPS

Ad

so

rptio

n o

f C

H4 [

mm

ol/g

]

a)

0 5 10 15 20 25 30 35 40 45

0

2

4

6

Pressure [bar]

25 40

60 80

100 120

140 160

SIPS

Ad

so

rptio

n o

f C

H4 [

mm

ol/g

]

b)

Figure 1. Methane adsorption on the carbons: a) KOH:CWZ-22_850=4; b) K2CO3:CWZ-22_850=4 at different

temperatures; The symbols denote experimental results, lines were determined based on the Sips model

The course of the methane adsorption isotherms was typical for the physical adsorption.

The amount of gas adsorbed on the carbons was relatively quickly increased at lower

pressures, whereas the adsorbed gas amount was progressively decreased along with

adsorption progress at high range of pressures. An increase in temperature caused a decrease

in the methane adsorption at a given pressure.

A value of the isosteric heat of adsorption as a function of the degree of surface coverage

in the presented investigations were estimated under different temperatures with the

utilization of the Clausius-Clapeyron equation. In order to determine the isosteric heat of

adsorption were performed the plots of dependence ln(p) on 1/T for a given degree of the

surface coverage in the range from 0.005 to 0.035. The isosteric heat of adsorption for

analyzed activated carbons was in the range from 23 to 16 kJ/mol. Such values confirm the

proceeding of the physical adsorption. The isosteric heats of adsorption varied in a slight

degree along with a change of the degree of surface coverage which indicates that the surface

heterogeneity is small in relation to methane adsorption.

The studies demonstrated that a modification of the commercial activated

CWZ-22 carbons by KOH and K2CO3 leads to the enhancement of the porous structure of

used carbons and causes the increase of the methane adsorption.

References:

[1] D. Lozano-Castello, J. Alcaniz-Monge, M.A. de la Casa-Lillo, D. Cazorla-Amoro´s, Linares-Solano, Fuel 81,

(2002) 1777–1803.

[2] D.F. Quinn, J.A. MacDonald, Carbon 30(7) (1992) 1097-1103.

[3] M. Bastos-Neto, A.E.B. Torres, D.C.S. Azevedo, C.L. Cavalcante, Adsorption 11 (2005) 911.

[4] M.J. Prauchner, F. Rodriguez-Reinos, Micropor Mesopor Mat 109 (2008) 58

74

Tailoring the textural properties of an activated carbon

J. Sreńscek-Nazzal, K. Kiełbasa




Recently, there is increasing research interest in the utilization of the activated carbons

associated with the necessity of continuous improvement of their quality in numerous

industrial processes. The activated carbons due to strongly developed specific surface area,

well developed pore system as well as exeptional physicochemical properties are attracting

more and more attention in almost all industry branch. Undoubtedly, the most important

among many applications is their usage as adsorbents, catalysts or electrode material for novel

energy sources. It is not surprising then that various types of the activated carbons

modifications are still being made. These procedures are concern on the acid-based, catalytic

and textural properties which in a significant degree determine the adsorption purpose. In

order to determine the appropriate adsorbents the modification methods concerning a search

of the enhancement of the porous structure i. e. specific surface area, the pore volume as well

as the micropore volume have to be chosen.

The modification of commercial activated WG-12 carbon (GRYFSKAND, Ltd., Poland)

for the gas adsorption processes is presented. The activated carbon was modified by

a saturated solution of KOH and K2CO3 for 3h. The mass ratio of the modifying agent to

carbon (M:C) was varied in the range from 1 to 4. The WG-12 carbon was modified in the

temperature range of 600-850 oC. The process was performed under nitrogen atmosphere

(flow of 18 dm3/h). The achieved activated carbon containing the decomposition products of

potassium hydroxide or potassium carbonate were washed with distilled water to achieve a

neutral reaction. Afterward, the activated carbon was dried at temperature of 110 oC for 16h.

Considering the evaluation of the textural properties of activated carbons modified by KOH

and K2CO3, the low-temperature adsorption isotherms of N2 (-196 oC) were determined by

means of volumetric adsorption analyzer Quadrasorb Evo (Quantachrome Instruments). The

control and data acquisition enabled the QuadraWin software. In order to remove the

pollutants prior to the adsorption measurements the carbon samples were heated at

temperature of 250 oC for 12h under the conditions at reduced pressure. An apparatus

MasterPrep coupled with computer was utilized for this purpose. From N2 sorption isotherms,

the following parameters characterizing the porous structure have been determined:

• surface area SBET calculated from the BET equation in the range of partial pressure of

p/p0=0.05-0.2;

• total pore volume Vp,(N2) determined on the basis of the maximum adsorption of

nitrogen vapour for a value of p/p0=0.99;

• pores within a range of micropores Vmic,(N2) and mesopores were determined by

means of N2 analysis at temperature at -196 oC using the DFT method (density

functional theory). The N2 adsorption isotherm at -196 oC provides information

concerning the micropore structure with a width over 1.5 nm and the mesopores, and

partially macropores;

• the measurements of pores with smaller diameters (0.3-1.47 nm, Vmic(CO2)) were

performed using CO2 at 0 oC.

The adsorption isotherms of N2 (-196 oC) obtained for the initial WG-12 carbon and the

carbons modified by KOH and K2CO3 in the temperature range of 600-850 oC (the ratio of

modifying agent to carbon equals to 1) were presented in Figure 1.

75

0.0 0.2 0.4 0.6 0.8 1.0

200

300

400

500

P/ P0

Va

ds S

TP

[cm

3g

-1]

WG-12

KOH:WG-12_600=1

KOH:WG-12_650=1

KOH:WG-12_700=1

KOH:WG-12_750=1

KOH:WG-12_800=1

KOH:WG-12_850=1

a)

0.0 0.2 0.4 0.6 0.8 1.0

200

300

400

P/ P0

Va

ds S

TP

[cm

3g

-1]

WG-12

K2CO

3:WG-12_600=1

K2CO

3:WG-12_650=1

K2CO

3:WG-12_700=1

K2CO

3:WG-12_750=1

K2CO

3:WG-12_800=1

K2CO

3:WG-12_850=1

b)

Figure 1. The adsorption isotherms of N2 (-196 oC) for carbon modified by a) KOH, b) K2CO3

The isotherms tested demonstrated a high adsorption of N2 at low relative pressure that is

characteristic for the microporous materials. It was noticed, that the nitrogen adsorption

capacity at temperature -196 oC significantly increased in the case of all the carbon samples

along with rising temperature of the thermal treatment during modification. From a viewpoint

of the IUPAC classification, the nitrogen sorption isotherms at the initial range of the relative

pressure p/p0 correspond to the Type I, whereas in the range of medium and higher pressures

to the Type IV.

The specific surface area, the total volume of pores and micropores were changed as

a result of modification of the activated carbons. It was found, that the specific surface area

increases along with increasing modification temperature from 600 oC up to 850 oC regardless

a kind of used modifying agent. The specific surface area values for the modified carbons by

KOH and K2CO3 were in the following ranges: 1128-1547 m2/g and1128-1388 m2/g,

respectively.

It was also evidenced that the total pore volume increases along with increasing

modification temperature in the case of each kind of the activated carbon. A pore volume

determined for the WG-12 carbons fluctuated in the 0.53-0.81 cm3/g range, whereas a more

intense increase of the total pore volume was observed in the case of carbons modified by

a larger amount of modifying component.

It was found, that the volumes Vmin,(N2) and Vmin,(CO2) have exhibited a growing tendency

with an increase in the modification temperature. A volume of micropores with the diameters

of 1.4-2 nm for the WG-12 carbon were in the following range 0.3-0.44 cm3/g. It was noticed,

that incorporation of a larger amount of modifying agent into the carbons did not cause

a significant increase of the micropore volume with the diameters of 1.4-2 nm. The Vmin,(CO2)

measurements demonstrated, that the volumes of micropores from a range of 0.3-1.4 nm, in

the case of modified activated WG-12 carbons were in the 0.18-0.27 cm3/g range. It was

found that a larger amount of modifying agent influenced in a slight degree on a growth of

Vmin,(CO2) volume analogous to the case of Vmic(N2) measurements.

The studies show that a modification of the commercial activated WG-12 carbon by KOH

and K2CO3 provides the development of the textural properties of used carbons and causes the

increase of the adsorption capacity.

References:

[1] Z.W. Zhu, Q.R. Zheng, Appl Therm Eng 108 (2016) 605–613

76

Activated carbon prepared from mistletoe leaves

A. Szymańska

Instytut Technologii Chemicznej Nieorganicznej i Inżynierii Środowiska, Zachodniopomorski Uniwersytet

Technologiczny w Szczecinie, ul. Pułaskiego 10, 70-322 Szczecin


Almost all materials with high elementary carbon content and low inorganic (i.e. ash)

amount can be used as precursors for the production of activated carbons (ACs). Waste

biomass from agricultural and wood or food industry has proved to be promising raw

materials for the production of ACs in view of their low price and high availability [1–3].

The precursor of carbon was dried mistletoe leaves, which were ground and mixed with a

saturated solution of potassium hydroxide. The activator was added to the precursor in a mass

ratio of 1:1. The mixtures were left at room temperature and atmospheric pressure for 3 h and

then dried at 200 °C for 19 h. Afterward, the obtained materials were placed in a tubular

furnace and carbonized at temperatures from 550 °C to 900 °C under a nitrogen flow of 3.8

dm3/min. After the carbonization process, the samples were washed with deionized water to a

pH of about 6.5 and then treated with a solution of hydrochloric acid (1 mol/dm3) for 19 h.

The final stage was re-washing materials with deionized water and drying for 19 h at 200 °C.

The obtained activated carbons were denoted as ML550 – ML900.

In order to the textural characterization of the obtained ACs, nitrogen adsorption-

desorption isotherms were determined at a temperature of -196 °C. The specific surface area

(SSA) was calculated using the BET equation. The DFT model was applied to determine the

micropores volumes (MPV) and the pore size distributions (PSD) from the N2-adsorption

data. The total pore volume (TPV) was determined from the amount of adsorbed nitrogen at a

relative pressure of approximately 1.

The textural properties of obtained ACs were presented in Tab. 1. The specific surface

area values of the obtained materials ranged from 394 to 1779 m2/g. The specific surface area

and total pore volume of ACs increased with the rise of the carbonization temperature. The

TPV and MPV values were in the range 0.245 – 1.159 cm3/g and 0.167 – 0.482 cm3/g. The

MPV values also showed an upward trend with an increase of carbonization temperature up to

850 °C.

Table 1. Textural properties of activated carbons

Material ML550 ML600 ML650 ML700 ML750 ML800 ML850 ML900

SSA [m2/g] 394 505 598 937 1220 1218 1731 1779

TPV [cm3/g] 0.245 0.368 0.427 0.635 0.696 0.701 1.102 1.159

MPV [cm3/g] 0.167 0.216 0.255 0.394 0.463 0.434 0.482 0.451

Fig. 1 presented the nitrogen adsorption-desorption isotherms of ACs. The isotherms for

materials carbonized at temperatures of 550 – 800 °C were classified as type I, and exactly

I(a) for materials ML550, ML600, ML650 and type I(b) for materials ML700, ML750,

ML800, according to IUPAC classification. The obtained isotherms testify to a well-

developed microporous structure. In the case of a material ML850 and ML900, the isotherms

were a combination of type I(b) and IV(a) with H4 hysteresis loop, indicating the existence of

micro- and mesopores in the structure.

77

0,0 0,2 0,4 0,6 0,8 1,0

100

200

300

400

500

600

700

800

ML900

ML850

ML750ML800

ML700

ML650

ML600

ML550

N2 a

dsor

ptio

n [c

m3 /g

]

p/p0

Fig. 1. Nitrogen adsorption-desorption isotherms for obtained ACs

Fig. 2 and Fig. 3 showed the pore size distributions of the obtained materials determined

from nitrogen adsorption isotherms. The pore volume tended to gradually decrease with the

pore diameter in almost all materials. This results confirmed the dominant content of

micropores, as well as the presence of mesopores less than 2,5 nm in diameter in all ACs

except ML850 and ML900, which in their structure had larger mesopores with the diameter

up to 6 nm (ML850) and 9 nm (ML900).

1 2 3 4 5 6

0,00

0,05

0,10

0,15

0,20

0,25

0,30 ML550

ML600

ML650

ML700

dV

/dD

[cm

3/n

m/g

]

Pore diameter [nm]

1 2 3 4 5 6

0,00

0,05

0,10

0,15

0,20

0,25

0,30

0,35

0,40

ML750

ML800

ML850

ML900

dV

/dD

[cm

3/n

m/g

]

Pore diameter [nm]

Figure 2. The pore size distributions of ML550 –

ML700 (D – pores diameter)

Figure 3. The pore size distributions of ML750 –

ML900 (D – pores diameter)

Activated carbons prepared from mistletoe leaves by chemical activation with potassium

hydroxide have a well-developed microporous structure. All examined materials showed the

presence of pores with a diameter from 0.4 to 9 nm, while pores with diameter below 3 nm

occupied the largest volume in every case. Due to their textural properties, obtained ACs

might be used in adsorption processes.

References:

[1] S. Hussain, K.P. Anjali, S.T. Hassan, P.B. Dwivedi, Appl. Water Sci. 8 (2018) 165.

[2] E. Koseoğlu, C. Akmil-Başar, Adv. Powder Technol. 26 (2015) 811–818.

[3] O. Ioannidou, A. Zabaniotou. Renew. Sust. Energ. Rev. 11 (2007) 1966–2005.

78

INDEKS AUTORÓW

A

Aleksandrzak M. ................................................ 19, 41, 64

Atraszkiewicz R. ............................................................. 16

Augustyniak-Jabłokow M. ............................................. 14

B

Baca M. .......................................................................... 41

Backes C. ....................................................................... 29

Barsoum M.W. .............................................................. 28

Biegun M. ................................................................ 70, 71

Binder J. ...................................... 24, 30, 37, 38, 43, 44, 60

Birowska M. ................................................. 33, 34, 35, 61

Blau W. .......................................................................... 29

Bożek R. ......................................................................... 43

C

Cendrowski K. .......................................................... 63, 66

Chen H. .................................................................... 67, 68

Chen X. .............................................................. 45, 69, 71

Chlubny L. ...................................................................... 53

Chudy M. ................................................................. 28, 53

Ciecholewska D. ............................................................ 47

Ciesielska A. ............................................................. 12, 58

Ciesielski D. .................................................................... 12

Ciesielski W.................................................................... 58

Coleman J.N. .................................................................. 29

Czarniewska E. ............................................................... 36

Czelej K. ......................................................................... 23

Czeppe T. ......................................................................... 8

Czerniak-Łosiewicz K.......................................... 26, 40, 57

D

Danovich M. .................................................................. 30

Dąbrowska A.K. ............................................................. 44

Dąbrowski P. ............................................................ 38, 59

Drabińska A. .................................................................. 24

Drabowicz J.................................................................... 12

Dudyński M.................................................................... 62

Dybowski K. ................................................................... 16

F

Fal’ko V.I. ....................................................................... 30

Faugeras C. .................................................................... 30

Fedaruk R. ..................................................................... 14

Furman M. ..................................................................... 37

G

Gacka E. ................................................................... 17, 55

Geim A.K. ...................................................................... 30

Gertych A.P. ............................................................ 40, 57

Gliźniewicz M. ............................................................... 47

Gmitra M. ...................................................................... 59

Godlewski S. .................................................................. 20

H

Harputlu E. .................................................................... 13

Howarth J. ..................................................................... 30

I

Iwański J. ....................................................................... 43

J

Jamróz A. ................................................................. 32, 62

Jankowska A. ................................................................. 34

Jastrzębska A.M. ..................................................... 28, 53

Jeziorna A. ..................................................................... 16

Jędrzejczak-Silicka M. ................................... 19, 36, 47, 49

Judek J. ......................................................... 26, 40, 57, 60

Jurkiewicz K. .................................................................. 62

K

Kaleńczuk R.J. ................................................................ 41

Kamińska M. .................................................................. 24

Kargul J. ......................................................................... 13

Kaszub W. ...................................................................... 24

Kaźmierczak T. ............................................................... 16

79

Kiełbasa K. ............................................................... 72, 74

Kierdaszuk J. .................................................................. 24

Kiliszek M. ...................................................................... 13

Klusek Z. ............................................................ 37, 38, 59

Kolman A. ...................................................................... 21

Kołodziej J.J. .................................................................. 59

Kołodziejczyk Ł. ............................................................. 16

Kondej D. ....................................................................... 51

Kopciuszyński M. ........................................................... 59

Korznikova G. .................................................................. 8

Koshevarnikov A. ........................................................... 23

Kowalczyk P. .................................................................. 16

Kowalska D. ................................................................... 13

Kowalski G. .............................................................. 24, 44

Kozieł K. ................................................................... 12, 58

Kozikov A. ...................................................................... 30

Krajewska A. .................................................................. 24

Kubas A. ................................................................... 21, 55

Kukułka W. .............................................................. 63, 66

Kula P. ............................................................................ 16

Kulawik D. ................................................................ 12, 58

Kunstmann J. ........................................................... 33, 61

L

Larowska D. ............................................................. 17, 21

Lewandowska-Andrałojć A. ............................... 17, 21, 55

Litynska-Dobrzynska L. .................................................... 8

Liu X. .............................................................................. 69

Ludwiczak K. .................................................................. 38

Lutsyk I. ............................................................. 37, 38, 59

Ł

Łacińska E.M. ..................................................... 37, 38, 59

Łapińska A. .................................................................... 42

M

Mabrouk M.................................................................... 54

Mackowski S. ................................................................. 13

Majewski J.A. ............................................... 23, 32, 54, 62

Małolepszy A. .......................................................... 17, 55

Marciniak B. ....................................................... 17, 21, 55

Maślana K. ......................................................... 65, 70, 71

Mazurkiewicz-Pawlicka M. ................................ 17, 21, 55

Michalkiewicz B. ............................................................ 66

Mijowska E. . 19, 36, 45, 49, 63, 64, 65, 66, 67, 68, 69, 70,

71

Molas M.R. .................................................................... 30

Mrówczyńska L. ............................................................. 36

N

Natu V. .......................................................................... 28

Necio T. ......................................................................... 35

Novoselov K.S. ............................................................... 30

Nowak D. ....................................................................... 16

Nowicki P. ...................................................................... 36

O

Ocakoglu K. ................................................................... 13

Olszowska N. ................................................................. 59

Olszyna A. ................................................................ 28, 53

Ozga P. ............................................................................ 8

P

Pakuła K. ....................................................... 24, 43, 44, 60

Pavliuk V. ....................................................................... 58

Piotrowska K. .......................................................... 19, 49

Potemski M. .................................................................. 30

Poźniak S. ................................................................ 28, 53

Przewłoka A................................................................... 24

R

Rogala M. ................................................................ 38, 59

Rogoża J. ....................................................................... 60

Romaniak G. .................................................................. 16

Rozmysłowska-Wojciechowska A. .......................... 28, 53

S

Scheibe B. ...................................................................... 28

Sielicki K. ................................................................. 19, 64

Siemion A. ..................................................................... 42

Sobanska M. .................................................................. 24

Socha R. ........................................................................... 8

Sosnowski T.R. ............................................................... 51

Sreńscek-Nazzal J. ................................................... 72, 74

Stępniewski R. ........................................ 37, 38, 43, 44, 60

Stobiński L. ......................................................... 17, 21, 55

Strzelczyk R. .................................................................. 14

Szalkowski M. ................................................................ 13

Szalowski K. ................................................................... 59

Szuplewska A. .......................................................... 28, 53

Szydłowska B.M. ........................................................... 29

Szymańska A.................................................................. 76

Szymoński M. ................................................................ 20

80

Ś

Świniarski M. ..................................................... 26, 40, 57

T

Tadyszak K. .................................................................... 14

Taniguchi T. ................................................................... 30

Tokarczyk M. ........................................................... 24, 44

Trukawka M. ...................................................... 36, 49, 63

U

Unlu C.G. ....................................................................... 13

W

Wang T. ................................................................... 67, 68

Watanabe K. .................................................................. 30

Wen X. ..................................................................... 67, 68

Wen Y. ........................................................................... 45

Wenelska K. ............................................................. 70, 71

Withers F. ...................................................................... 30

Wiwatowski K. ............................................................... 13

Wojciechowski T. .......................................................... 53

Wójcik A. ................................................................. 21, 55

Wróbel R.J. .................................................................... 10

Wróblewska A. .............................................................. 26

Wysmołek A. ........................ 24, 30, 37, 38, 43, 44, 59, 60

Z

Zdrojek M. .......................................................... 42, 57, 60

Zemła M. ....................................................................... 23

Zgrzebnicki M. ............................................................... 10

Zielińska B. .................................................................... 41

Ziemkowska W. ............................................................. 53

Zuzak R. ......................................................................... 20

Zytkiewicz Z.R. ............................................................... 24

Ż

Żarska S. ........................................................................ 12

Żerańska-Chudek K. ....................................................... 42

Żurawek L. ..................................................................... 59

5 Polish Conference „Graphene and 2D...

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